I would like to re-explore the motivation behind #17900, which was a workaround for a bug in tox, that we apparently misidentified: the original bug report was closed as resolved, but we were actually still able to reproduce the problem in #19325.
I have some small hope that going rid of the legacy tox.ini configuration might be a way out of this problem (#19334), so I'd like to re-explore it when tox.toml is viable.