If by “are using PEP-517 build systems” you just mean those that use pyproject-rpm-macros
in their spec files, I can also offer python-asyncpg and python-pyrsistent as examples.
If you mean that upstream does not use setuptools in setup.py, but instead uses flit or
poetry via pyproject.toml, then python-pendulum, which uses poetry, may be the only
example right now.