But if uctags still generates the parent_kind:A::B::C form the problem will still apply in the case of ctags generated files without sZ so needs to still be able to read those files. And document the ctags option as recommended somewhere.
The documentation is a good point, I'll write something.
How "slow" is it in reality? After all tags are only read once, even seconds is likely to be acceptable.
I haven't benchmarked that, it probably just "doesn't feel right" than being some real problem.