So, I had a look at the source .dmg on my Mac Monterey. And it 'appeared' as if it was going to install fine. In fact, I am somewhat certain its the same one as already installed (a year or so ago?).
The dmg itself is not just a straight forward tar/zip/whatever of the files as I expected. Firstly, it forces you to agree to the license and then seems to have a possibly unusual * compression used on the data. Maybe Apple has decided to block either that agreement model (?) or dropped support for that compressor ?
Then it seems to want to "run" an installer, when all that is needed is a drag n drop into /usr/local/share/.
Anyway, it needs to be solved. Easiest approach would be for me to send you a tarball of the FPC 3.2.4-rc1 and another of its source. You almost certainly want to be using that, not fpc3.2.2. But it won't solve the problem, just work around it.
I could try and package the source using the same packaging tools I use for my application, will take a bit of time but I can put that time in IFF there is someone at the other end who can test it and give some meaningful feedback. That would, at least, give us an indication that the packaging model used back in 2021 has passed its use-by date ? If we can prove the installer is at fault, it would be worth logging a bug report.
Who wants to play ?
* Nothing I say wrt MacOs should be taken, in any way, as authoritative !
Davo