Debian freezes and maintains versions during release cycles for any package of a Debian release.
We will likely port to the next version of XFCE when porting Whonix from its current base distribution Debian buster to the upcoming/next release of Debian (codename bullseye) which might be in ~ 2 years from now.
That would actually be very useful if someone tested that so that newer XFCE versions do not introduce bugs which are blockers for Whonix. Because by the time we port, it might be to late to report bugs and see them fixed in the next stable of Debian.
Your testing in Whonix 15 is blurry compared to Whonix 14? - #4 by AnonymousUser is appreciated. If you don’t test it, probably nobody else is testing it either. By the time we’re trying to port Whonix to the next stable of Debian we might run into bugs which won’t be fixed in time which then could cause big trouble at Whonix side. Testing now makes sure there is still enough time and no catastrophic bugs when time has come.
HiDPI, once and for all. (Appearance > Settings tab > Window Scaling to 2x, and then Window Manager > Style tab select a hdpi / xhdpi theme for the buttons.) This makes it much sharper text rendering for modern HiDPI monitors. It looks ‘clear’ where the current Xfce is ‘fuzzy’. It completely resolves Whonix 15 is blurry compared to Whonix 14? - #4 by AnonymousUser.
Small thing: Taskbar (‘panel’) items are finally non-dim and easier to read. Been a small bug for years.
Things it sadly doesn’t fix that I thought it might:
Mousepad failing to detect already open files when opening them from Thunar / Desktop.
No amazing new themes like I hoped. But Arc since Buster is great anyway.
There may be other improvements reported by the Xfce community, but I won’t spend time searching out for what they may be. I’m welcome to hear of any.
This changelog indicates possible video driver fixes (e.g. for video playback within Whonix), I have not tested yet.
Conclusion: it’s not the spectacular improvement I thought it’d be. However, for me it’s worth it alone for the HiDPI support.
So @Patrick, I understand if you don’t consider HiDPI support alone being worth implementing Xfce 4.14 into current Whonix packages (by emulating what the above isolated repo does). It does seem stable however, no issues noticed, I only needed to reboot the desktop environment after upgrading.
So that’s my report.
I may have more thing to report over time, e.g. I may test out video driver and video playback support. My recommendation to not wait another 2 years for Xfce 4.14 for the Whonix community may strengthen.