Agent interested in bringing me on board, all but demands Fi-core

Beyond title, some background:

- I am in the DC area, so most (if not every job) are non-union

- I am open to traveling to NYC and even Atlanta for bigger work but again would require SAG-AFTRA

- I am relatively new, but have been lucky in getting consistent work in shorts, a feature and commercials in the 9 or so months since I started

- edit: should note that I do have a job outside the craft that leaves me financially stable so I am not concerned about lack of healthcare etc. (for me personally, to say nothing of what I assume others need and I understand that difference)

I reached out to a talent agency in my area who said they would be very interested in bringing me on board but says they would only accept if I wanted to quickly join Ficore. I will admit I had to do some research for a few hours to understand but I think I have a solid grasp, at least conceptually, of the differences between the two.

Am I making unalterable career mistakes by doing this just as I am starting out? Or can I join SAG-AFTRA later with a more established resume after ficore?

I am genuinely open to both and told the agent I needed a little time to think it through.

Help?