Chili Rasboro and RCS?

You just answered your own question.

If you have shrimplets, they'll get eaten.

BUT - I keep Chili Rasboras (Boraras brittae) with Neo shrimp and have a thriving colony. Many times, the adult fish are smaller than adult shrimp.

Yea my RCS colony is huge now, lotsa berried ones. I used to keep CPD with them, and they did okay, def. didn't thrive like they do without fish. I thought with Chili's they might be able to increase population still, just not as fast.

While Chilis will definitely hunt for and pick off babies, you won't notice too much of a dent in your population if it's already well-established.

Just know that these fish are so tiny they can get into the nooks and crannies of just about any tank.

If you really wanted to be safe, you could put berried shrimp in a breeder box or net and keep the babies there until they're too big for the fish to devour.

They will grow in numbers a little slower, but they reproduce fast anyway and the fish will get some good live food here and there!!!

Okay cool, at this point I have moved on from wanting a shrimp only tank to wanting an entertaining tank to watch. I think a nice sized shoal of these chili's would be cool but the question I have now is how many can I put in the tank? 10-12ish?

I think you could easily handle 15-20 in a 10gal tank. They're waaaay tinier than most people expect.

They had maybe, 3 dozen in the LFS. really pretty looking. I loved how they all kinda floated together in some watersprite they had in the tank. slowly floating out looking at things.

They aren't much a schooler, at least in the number I kept them in (8 in a Mini-L) but I agree, you could probably have around 15 in a 10 gallon.