Inherit Alpha is something I use very often in while working in Krita (and before that, in Paint Shop Pro where it was called “Lock Transparency”). What it does is prevent a layer from making any changes to the alpha channel. Effectively, it’s a bit like making a mask from a merge of all lower layers, except far more convenient because you don’t have to remake the mask every time you change anything in the lower layers.
You’d be amazed how often this comes in handy. It’s my go-to when I want to add lighting/shadows with a big soft brush in a new layer without having it spill out over pixels that should be fully transparent. It would be really nice to have it in Aseprite too.