But the original "main.qml" is also installed in the standard location. Should I just create a separate branch for kirigami ui and remove the original main.qml in that?

In D5945#111704, @atulsharma wrote:

But the original "main.qml" is also installed in the standard location. Should I just create a separate branch for kirigami ui and remove the original main.qml in that?

just install it in a separate folder.

a thing you can do is to use kpackage to load it instead, which would load from a completely differen installed folder