It's my first time posting here so i'm not sure if this is something you already have thought about, but i was setting up supports for a very detailed model where in many cases wished i could just have something like a paint tool where you can use a brush that you can change the size of in chitubox to attach close by islands on the current layer to the model, instead of having to somehow get a support up in there. And with that i mean a paint brush where you paint on the current layer (2d).
I agree that a tool like this is badly needed. Ideally I would like to select a surface, select a second surface, then be able to select the type of support I want to add between them. I just spent the best part of 12 hours trying to add supports to a model and everytime I tried to add a support it added a full length support when a simple mini-support between 2 surfaces would have been enough.