You made your decision already, but you didn't consider the most important factor(s) imo. Rocky is 1:1 bug for bug compatible with RHEL, i.e. it's a clone. Alma is now only 'ABI compatible' with RHEL, meaning it bases from RHEL but can have other changes on top. That can be a good thing (they can add patches or security fixes either before RHEL, or that RHEL refuse to implement), or a bad thing (trusting their decisions and code, diverging from RHEL codebase), depending on your views and your needs. I found recently that Alma ended up running a different kernel than Rocky/RHEL and the two diverged.
Alma does tend to release much faster than Rocky, but not enough to care in a production environment. As above, Rocky is privately owned and Alma is more 'open', but in practice it shouldn't matter as both operate as FOSS. Both are active projects and both have their selling points. The repos differ slightly from each other and their respective SIGs have their own differing merits. In prod, I now exclusively use and prefer Rocky, but it was almost a coin toss. Short of FTSE100 type territory it's pretty irrelevant and both will do a decent job.
Regarding your comment about it being too difficult to change your mind later, however, that's not true. Both projects have excellent scripts that will live migrate machines in-prod with a simple reboot. I've switched in-prod machines from one to the other and back again without issue. It's basically just artwork, release naming and repo tweaks in /etc/yum/repos.d
. So, bear in mind you're not lost if you decide later you should have picked the other distro (or one goes belly up).