Is there truly no way to simplify that process?

I see some software development possibilities which could improve
the communication with high volume mailing lists.

You should be sending the patches directly with SMTP using git-send-email,

This tool is also fine for the publishing of a lot of patches.

if you're not, then you're making things overly complicated for yourself.

But I prefer a graphical user interface for my mail handling so far.

Having a feature doesn't mean that it should be used.

Does any of the "questionable functionality" get occasionally overlooked
a bit too often?

Regards,
Markus