Right, I’m very well familiar of how it works in Lr, haven’t touche C1 in a while. I’ll install them and all the other programs I can find and I’ll do a features and UX comparison and create an issue on GitHub for future reference. Personally I’d be happy with a basic raster brush with “auto-masking” aka edge detection and flow change based on the pen pressure.
But if it would be of any use I can provide the use cases for some additional features like mask feathering (not to be confused with edge feathering) and other things so you can pick what you think most people will find useful.