Given something like some.path.@process.rule<caret> = … I suggest an action to break that into

some.path.@process.rule {
  expression = …
}

to allow easier addition of @if rules.
Maybe there is a stronger relationship to #8 however @process rules have this special behavior of having an expression key.

Maybe if the block is empty there could be an inlining action, however that depends on overrides:
it is not possible to override @process.rule.expression by @process.rule (fusionpen),
but it is possible to override @process.rule by @process.rule.expression (fusionpen).