I don't know what browser or email client add-ons for DeepL there are.
However, it seems all such gadgets just send the text to DeepL servers
for translation. Making it a nasty SaaS (service as a software
subsitute).
Btw, I don't want you to feel *nagged* by me to drop the Icedove addon
immediately. That's not how freesw community should work :) Tolerance
is important. I just wanted to clarify things
At the moment I don't know how to solve that?
I'll just blindly repeat what has been suggested on this list by others
before. That profile updates like this are not reliable (as you see)
and a better approach is to use construct your profile by declaring the
package set using a manifest as described here[1].
I don't know the "Weblate" thing you wrote about at the end, so I
cannot help here
Good luck once again!
Wojtek
[1]
https://guix.gnu.org/en/cookbook/en/guix-cookbook.html#Basic-setup-with-manifests