As requested, I've been running the stable-proposed-updates during the last three days.
Running Whonix VMs:
sys-Whonix: a crucial element in my Qubes infrastructure, since I use it for upgrading all the templates.
anon-Whonix: browsing (Tor Browser 6.5a3-hardened)
irc: chatting with friends.
Kind of tests performed:
Daily use + Whonix Check on any single VM.
No issues or anomalies detected. My laptop is running just fine.
However, if the Whonix team need to know something of more specific, I will be glad to help.