The current expectation on the mailing list is 5.4 should be generally backwards compatible with 5.3. Incompatibilities with 5,3 are listed in the manual:
This was created and tested on Ghost BSD (11.1-p4). I have a clean VM for 11.1 and a TrueOS VM (Some version of CURRENT) that I will test this on. I'll pull out an arm board if I can.
- I ran some heavy garbage collector tests on work1 that chewed up 8gb of memory without issue
- I would like to request @dbn for a expeditionary run to look at bumping all ports possible to 5.4.