diff --git a/Taskfile.yml b/Taskfile.yml
index 3e31fbd1250e..dd10a5411d34 100644
--- a/Taskfile.yml
+++ b/Taskfile.yml
@@ -100,7 +100,7 @@ tasks:
         {{.SERVICES}}
 
   env-setup:
-    deps: [gen-version]
+    deps: [gen-version, build-envtool]
     cmds:
       - bin/envtool{{exeExt}} setup
 
@@ -143,6 +143,7 @@ tasks:
       - go generate -x ./build/version
 
   build-envtool:
+    run: once
     cmds:
       - go build -v -o bin/ ./cmd/envtool/
 
@@ -151,6 +152,7 @@ tasks:
     run: once
     deps: [gen-version]
     cmds:
+      - echo 'build-host' > build/version/package.txt
       - go build -v -o=bin/ferretdb{{exeExt}} {{.RACE_FLAG}} -tags={{.BUILD_TAGS}} -coverpkg=./... ./cmd/ferretdb
       - bin/envtool{{exeExt}} shell mkdir tmp/cover
 
diff --git a/cmd/envtool/envtool.go b/cmd/envtool/envtool.go
index 7151b25ce198..a24ce448a890 100644
--- a/cmd/envtool/envtool.go
+++ b/cmd/envtool/envtool.go
@@ -33,7 +33,6 @@ import (
 	"time"
 
 	"github.com/alecthomas/kong"
-	"github.com/jackc/pgx/v5"
 	"github.com/prometheus/client_golang/prometheus"
 	"go.uber.org/zap"
 
@@ -99,6 +98,8 @@ func setupAnyPostgres(ctx context.Context, logger *zap.SugaredLogger, uri string
 		return err
 	}
 
+	// TODO https://github.com/FerretDB/FerretDB/issues/3452
+
 	var pgPool *pgdb.Pool
 
 	var retry int64
@@ -119,17 +120,6 @@ func setupAnyPostgres(ctx context.Context, logger *zap.SugaredLogger, uri string
 
 	defer pgPool.Close()
 
-	logger.Info("Creating databases...")
-
-	for _, name := range []string{"admin", "test"} {
-		err = pgPool.InTransaction(ctx, func(tx pgx.Tx) error {
-			return pgdb.CreateDatabaseIfNotExists(ctx, tx, name)
-		})
-		if err != nil && !errors.Is(err, pgdb.ErrAlreadyExist) {
-			return err
-		}
-	}
-
 	return nil
 }
 
diff --git a/internal/backends/collection.go b/internal/backends/collection.go
index ba41ed6fc1d7..6f0e6e1bad34 100644
--- a/internal/backends/collection.go
+++ b/internal/backends/collection.go
@@ -73,7 +73,8 @@ func CollectionContract(c Collection) Collection {
 type QueryParams struct {
 	// TODO https://github.com/FerretDB/FerretDB/issues/3235
 	Filter        *types.Document
-	OnlyRecordIDs bool // TODO https://github.com/FerretDB/FerretDB/issues/3490
+	OnlyRecordIDs bool   // TODO https://github.com/FerretDB/FerretDB/issues/3490
+	Comment       string // TODO https://github.com/FerretDB/FerretDB/issues/3573
 }
 
 // QueryResult represents the results of Collection.Query method.
diff --git a/internal/backends/postgresql/query.go b/internal/backends/postgresql/query.go
index d8729972e1db..41674fa1d1c5 100644
--- a/internal/backends/postgresql/query.go
+++ b/internal/backends/postgresql/query.go
@@ -33,6 +33,7 @@ import (
 // prepareSelectClause returns simple SELECT clause for provided db and table name,
 // that can be used to construct the SQL query.
 func prepareSelectClause(db, table string) string {
+	// TODO https://github.com/FerretDB/FerretDB/issues/3573
 	return fmt.Sprintf(
 		`SELECT %s FROM %s`,
 		metadata.DefaultColumn,
@@ -59,6 +60,9 @@ func prepareWhereClause(p *metadata.Placeholder, sqlFilters *types.Document) (st
 			return "", nil, lazyerrors.Error(err)
 		}
 
+		// Is the comment below correct? Does it also skip things like $or?
+		// TODO https://github.com/FerretDB/FerretDB/issues/3573
+
 		// don't pushdown $comment, it's attached to query in handlers
 		if strings.HasPrefix(rootKey, "$") {
 			continue
diff --git a/internal/handlers/common/delete_params.go b/internal/handlers/common/delete_params.go
index 126fdeda8282..36346f34c155 100644
--- a/internal/handlers/common/delete_params.go
+++ b/internal/handlers/common/delete_params.go
@@ -28,8 +28,8 @@ type DeleteParams struct {
 	DB         string `ferretdb:"$db"`
 	Collection string `ferretdb:"delete,collection"`
 
-	Comment string   `ferretdb:"comment,opt"`
 	Deletes []Delete `ferretdb:"deletes,opt"`
+	Comment string   `ferretdb:"comment,opt"`
 	Ordered bool     `ferretdb:"ordered,opt"`
 
 	Let *types.Document `ferretdb:"let,unimplemented"`
@@ -44,8 +44,6 @@ type DeleteParams struct {
 type Delete struct {
 	Filter  *types.Document `ferretdb:"q"`
 	Limited bool            `ferretdb:"limit,zeroOrOneAsBool"`
-	// TODO https://github.com/FerretDB/FerretDB/issues/2627
-	Comment string `ferretdb:"comment,opt"`
 
 	Collation *types.Document `ferretdb:"collation,unimplemented"`
 
diff --git a/internal/handlers/common/update_params.go b/internal/handlers/common/update_params.go
index 614ae57f8c95..d53469734b5a 100644
--- a/internal/handlers/common/update_params.go
+++ b/internal/handlers/common/update_params.go
@@ -25,9 +25,10 @@ import (
 //
 //nolint:vet // for readability
 type UpdateParams struct {
-	DB         string   `ferretdb:"$db"`
-	Collection string   `ferretdb:"update,collection"`
-	Updates    []Update `ferretdb:"updates"`
+	DB         string `ferretdb:"$db"`
+	Collection string `ferretdb:"update,collection"`
+
+	Updates []Update `ferretdb:"updates"`
 
 	Comment string `ferretdb:"comment,opt"`
 
@@ -43,8 +44,6 @@ type UpdateParams struct {
 //
 //nolint:vet // for readability
 type Update struct {
-	// TODO https://github.com/FerretDB/FerretDB/issues/2627
-	// get comment from query, e.g. db.collection.UpdateOne({"_id":"string", "$comment: "test"},{$set:{"v":"foo""}})
 	Filter *types.Document `ferretdb:"q,opt"`
 	Update *types.Document `ferretdb:"u,opt"` // TODO https://github.com/FerretDB/FerretDB/issues/2742
 	Multi  bool            `ferretdb:"multi,opt"`
diff --git a/internal/handlers/pg/msg_delete.go b/internal/handlers/pg/msg_delete.go
index 4d3d7babf157..0ba0ae8aa90b 100644
--- a/internal/handlers/pg/msg_delete.go
+++ b/internal/handlers/pg/msg_delete.go
@@ -60,7 +60,6 @@ func (h *Handler) MsgDelete(ctx context.Context, msg *wire.OpMsg) (*wire.OpMsg,
 	// process every delete filter
 	for i, deleteParams := range params.Deletes {
 		qp.Filter = deleteParams.Filter
-		qp.Comment = deleteParams.Comment
 
 		del, err := execDelete(ctx, &execDeleteParams{
 			dbPool,
diff --git a/internal/handlers/sqlite/msg_find.go b/internal/handlers/sqlite/msg_find.go
index 0a225c347797..c7cd292c7b90 100644
--- a/internal/handlers/sqlite/msg_find.go
+++ b/internal/handlers/sqlite/msg_find.go
@@ -66,7 +66,16 @@ func (h *Handler) MsgFind(ctx context.Context, msg *wire.OpMsg) (*wire.OpMsg, er
 		return nil, lazyerrors.Error(err)
 	}
 
-	var qp backends.QueryParams
+	qp := &backends.QueryParams{
+		Comment: params.Comment,
+	}
+
+	if params.Filter != nil {
+		if qp.Comment, err = common.GetOptionalParam(params.Filter, "$comment", qp.Comment); err != nil {
+			return nil, err
+		}
+	}
+
 	if !h.DisableFilterPushdown {
 		qp.Filter = params.Filter
 	}
@@ -81,7 +90,7 @@ func (h *Handler) MsgFind(ctx context.Context, msg *wire.OpMsg) (*wire.OpMsg, er
 	// closer accumulates all things that should be closed / canceled.
 	closer := iterator.NewMultiCloser(iterator.CloserFunc(cancel))
 
-	queryRes, err := c.Query(ctx, &qp)
+	queryRes, err := c.Query(ctx, qp)
 	if err != nil {
 		closer.Close()
 		return nil, lazyerrors.Error(err)