Thanks for the hint about Qt5 vs Qt6. Does not make sense indeed ,-)

IMO the ######################################################################### ... lines can be removed

The provides/obsoletes need to be versioned (see also rpmlint). Using %{version} should work in this case, the other package is at 4.2.0 ATM

The ldconfig stuff can be replaced by %ldconfig_scriptlets

FWICT the license is actually GPL-2.0-or-later?

Cool, thanks for your precise review, really appreciated.