I can't find brush engine selection in 4.0.0 version's brush editing screen. Where is it?

on the left side of the brush editor, there is an arrow that that shows/collapses all the brush preset. At the top of that area there is a drop down box to change the brush engine.

scottpetrovic wrote:on the left side of the brush editor, there is an arrow that that shows/collapses all the brush preset. At the top of that area there is a drop down box to change the brush engine.

What if I delete every single preset there is, how do I access these engines then?

Click the + to make a preset from scratch:

https://docs.krita.org/Loading_and_Savi ... et_Chooser