I have now upgraded from LMDE 5 to LMDE 6 on my explorer machine (ThinkPad T430s). I did not really have any additional installed there, and the upgrade with the Mint upgrade tool went well it seems.
TBD if I will swap from Mint (Ubuntu based) to this LMDE on my intended daily driver, or not. I'm slowly walking from macOS to Linux as daily driver. I am tempted to go for LMDE before I migrate too much.