For library development I target pure pip/setuptools but still use pipenv during development phase. There have been a few cases where pipenv had problems and I had to either remove my virtualenv and reinitialize it or even remove my pip-file/lockfile, but since I still have my setup.py it's not a big deal for me.
As for uploading etc I use twine but I wrap everything in a makefile to make handling easier.
A problem I noticed recently was a case where one of my developers used a tool which was implicitly installed in the testing environment since it was a subdependency of a testing tool but it was not installed into the production image. This resulted in "faulty" code passing the CI/CD and got automatically deployed to the live development environment where it broke (so it never reached staging). Caused a little bit of a headache before I found the cause.