My most popular Qt plugins should also be ready for Sigil 2.x and 1.x :
TagMechanic
DOCXImport
KindleImport
I tried to indicate in the plugins' first posts that when Linux users upgrade to (or build) Sigil 2.0 with Qt6, they'll need to install PySide6 (to use these Qt plugins). Since Linux Sigil relies on the system Python for plugins.