My Mac Mini is running 10.14 and I have noticed an OSX system warning dialog popping up to notify me that Indigo is not optimised and warning about it being an incompatible app. I believe my computer is warning me about 32 bit apps as Apple plan to only support 64 bit apps in future.
It would appear that Apple is hoping that by drawing attention to the compatibility issue it will encourage developers to get 64-bit versions of their apps ready.
Please can you tell me if this is on the Indigo roadmap?