Also, do you have any opinion on leaving x86_64 behind and going for RISC-V? Putting FreeBSD on a RISC-V board? It feels like that would be a wonderful freedom machine.
In freebsd you have the same software as in Linux thanks to the ports, the ports is nothing more than the adaptation of the source code of the Linux packages to compile in freebsd, since they comply with the posix standard there is hardly any adaptation to do.
Debian as of today has 34000 packages, freebsd ports 36000.
In addition, FreeBSD has support for Linux files and applications through its Linux compatibility subsystem (“Linuxulator”). This compatibility layer allows Linux binaries to run without modification.
https://wiki.freebsd.org/Linuxulator
In the case of SimpleX it is one of the few things that is not in the FreeBSD ports
Discussion
The problem is support, FreeBSD is characterized by its high performance on x86 architecture.
The arm and risc-v architectures have limited support on freebsd.