Is it safe full-upgrade (buster->bullseye)? (2 replies)

Hi guys!
I have debian buster on my good NSA325v2.
I've a lot of packages installed and configured for my purpose.
Is it safe to run a full-upgrade on this machine? I know the better way would be installDoozan bullseye image from scratch, but I don't want to spend much time on installing and configuring all of the packages I need.
Do you have suggestions?
Thank you in advance.
Kind regards.

Ivan