We (ZTF collaboration) are opening up an issue to identify our plans to perform a future merge request, to change how SNCosmo handles filters.

In our ZTF analysis, we have bandpasses that have positional dependence that is not radial. To this end, we need to implement bandpasses that have both positional and QE dependence. We have developed such a method for three instruments, and we are in the middle of testing consistency between this new method and the existing one.

Secondly, we would like to enable versioning for bandpasses - we are making some major updates to how we process our filters, so having SNCosmo support versioning would be a great boon. We are currently working on implementing this as well.

We hope to have an initial, tested fork by the week of the 21st of September, though this may not be the PR'd version.