Hi,
I am excited that exr/floating point support is coming. One additional feature that would be extremely helpful for us would be to support open colorIO (vs. ICC profiles).
In the visual effects industry, ICC profiles are hardly ever used (and can be a pain in the arse). Open ColorIO is our preferred color management and if we had the ability to natively use the same profiles that we use in Nuke, Mari, and Maya then we would be miles ahead of photoshop with its confusing and annoying color management.
As its name implies, it is an open standard. I have no idea how hard it would be to switch between the two different color models, but if it is at all possible it would push Affinity Photo forward in the effects field quite a bit (coupled with your support for floating point file formats).