Hello,
I tried a lot of different shrimp in Parosphromenus-tanks but only Caridina parvidentata grew well. So all what I say is connected to that species.
I never felt good with shrimp in a breeding aquarium, but I have a common tank in which they do their cleaning job and donate a snack from time to time (their fry). I had a lot of young Parosphromenus in that tank and Betta, too. I think young Paros better hide as Betta so I think it is possible to keep them together.
But I used a 160L tank and a lot of plants within, so you may try but keep an eye expecially to the early fry.
Good luck!