Lemmy v0.19.0 is introducing some breaking changes that, if I add support for in Photon, will break compatibility with instances before v0.19.0. If I don't add support for v0.19.0, instances with that version or higher will break. How should I proceed?

A: Keep an old version of photon available for people who need to use a pre-0.19.0 instance (medium difficulty)

B: Add a message to login saying the instance must be v0.19.0 or higher, nuke all backwards compatibility (easiest solution)

C: wait until most instances are on v0.19.0 to proceed with B

D: Add code to handle different versions (hardest solution)

I'd prefer that people be able to rely on Photon, and anything that prevents them from doing stuff on photon I see as a catastrophic issue. A looks the most appealing right now.