What advice do you have for someone considering transferring from Reserve PSYOP to active PSYOP or getting SFAS?

I’ve been retired for quite awhile, but think Special Forces is still an accession branch, i.e. you can’t be branched SF out of OCS. You would have to branch some other career field, serve successfully, then apply for SFAS, and successfully complete the course. If you transition to active duty PSYOP you may consider applying for SFAS; and if you succeed and make it to an SF Group, consider going the SF Warrant route. Going that path you’ll be able to stay in Group and the pointy end of the spear. Commissioned SF officers due their time in an SF Group, the end up serving in higher hqs staffs, as well as numerous SF billets throughout the Army. I know this from personal experience. Good luck whatever you choose to do.

If you go Regular Army, you still need to do PSYOP Accession & Selection, regardless if you are already 37F MOSQ (same MOS but different in context (blame proponent office and big army on that one); unless it changed after I retired. If you get commissioned, it will be in one of the basic branches and then as a 1LT promotable you can apply for SF, PSYOP, or CA if you like.

I'd cool your Rambo jets until Iran dies down.