Hello,
there is one thing about Krita that has been bugging me a lot for a very long time, though it should be relatively easy to fix:
The invisible hotspot for dropping a layer above or below another in the layers docker is absolutely tiny. It has a height of merely four pixels if I'm not mistaken. Compare that to Photoshop's layers panel and you'll notice how ridiculously fiddly Krita behaves in comparison.
I am rearranging layers constantly when working with Krita, and it is at times extremely difficult to drag and drop one layer between two others. So please double or triple the height of that layer drop area. (Highlighted here as a yellow box.)

I don't know how realistic this is, but I'd love to see this fix in the final 3.2.0 release if possible.
It would be a tremendous improvement to me as a professional artist (trying to completely ditch Photoshop in favor of Krita).

And while I'm already here, there's more things I've noticed:
When resizing the toolbox (which I like to have lying around loosely somewhere on the canvas), it should definitely always snap to the grid of the tool icons and never cut them.

Also, the grab area to resize the docker window is incredibly tiny. It makes resizing the docker unnecessarily challenging. (I guess that goes for all dockers.)

Thank you for reading this and considering my UI suggestions.

I haven't encountered the second issue, but agree about finding layers difficult to move accurately.