No, not Mat, XFCE:
What is irritating to me, is the outdated interface of Mint: Who wants to use Firebird 3?! Firebird 5 is stable,
Nicole, I am unsure what your problem is. If its that Linux Mint uses Firebird 3 instead of 5, thats absolutely nothing to do with the desktop (ie Cinnamon v. XFCe), either will be getting its Firebird from the same Linux Mint repo, its 3.
You could be, perhaps, be thinking of using the "Debian Edition of Linux Mint", cannot remember it correct name, its based directly on Debian Stable (and used XFCe) compared to eg 22.1 which is based on Ubuntu which is based on Debian Unstable. But, no, that will not help either, the current Debian Stable, Bookworm has Firebird 3. Interestingly, even Trixie the forthcoming release has Firebird 3 and 4. (just hit Hard Freeze by the way). Even Debian Experimental has Firebird 4, no sign of 5.
So, if you want Firebird 5 on any debian based machine, you need to install it directly from Firebird, maybe they have packages, maybe you will need to build from source. (You might find some third party packages, I'd suggest its risky.)
You could install Debian Trixie (as a pre-release or wait a couple of months,who knows ?) and that will get Firebird 4. The most recent short term Ubuntu (U25.04 ?) may have taken 4 from Debian Unstable, don't now, short term releases are too, er short term ?
If you are having some other problem using Lazarus on Cinnamon, need to tell us what, I just built a Linux Mint 22.1 Cinnamon VM, only thing I changed was switched to light theme, ran all updates. FPC324 and Lazarus 4.0 runs perfectly.
(I am very short of disk space so will need to remove that VM before long. No pressure.)
Davo