It turns out there's a need for a bugfix-only release nettle-3.4.1, to be released in a few weeks.
I've created a branch release-3.4-fixes, and backported a few bugfixes (see commit history or ChangeLog on that branch), https://git.lysator.liu.se/nettle/nettle/blob/release-3.4-fixes/ChangeLog
I'm sorry I haven't been able to respond to the recently posted patches on this list. I'll get back to that after 3.4.1.
If you think I've missed some important bugfixes, please speak up.
Regards, /Niels