Linux RDP with audio and mic
I have finally found the solution. Looking for an answer for the remmina client, a guy had xfreerdp working and not remmina and he posted his xfreerdp command here. The thing was that when I was launching the command with the two plugins (drdynvc and rdpsnd) I was also passing two data strings audin and pulse and that doesn't work. The solutions is passing two plugins with just audin as data:
xfreerdp -u user -d domain -p password --plugin drdynvc --plugin rdpsnd --data audin -- server
This seems to have been much improved in more recent versions of freerdp.
Now, just using the /sound /microphone:sys:alsa
options seem to work fine.
Once https://github.com/FreeRDP/FreeRDP/pull/3597 is merged, it'll be just /sound /microphone
again.
https://github.com/FreeRDP/FreeRDP/wiki/PreBuilds contains nightly builds which worked much better than my distribution's outdated packages.