Dear Maestro,
Your tank does indeed look very good! It is parially surprising that your plants grow so well… many (including myself) experience little growth and sometimes algae overtaking most of a tank. But you seem to be lucky! Also your male looks beautifully colored.
The tank you have is definitely large enough even for larger groups producing offspring. My tweediei are currently in a 25 liter tank and a 20 l. In the larger one, at least 4 males and 4 females are adult and from time to time, some of the offspring grow up. I guess at the time there are about 8 adults and 5+ subadults in it without problems.
I would only maybe consider not interbreeding your new bintan with the old cf. bintan male in case that they are not the same form/species. In that case you could easily keep the male with the other fish in your larger tank.
The main problem with keeping paros with other species is that often, freshly hatched offspring will be eaten by the other fish. H. amandae wont hesitate going after yout bintan fry i guess. Therefore, species tanks are favorable unless you know that there are always enough offspring to keep your stock alive.
Greetings Rafael