Did Polish citizens required to do military service after 1920 lose citizenship if they got it elsewhere?

As I understand it, people who became Polish citizens under the Citizenship Law of 1920 were required to do military service if they were adult men up until the age of 50. If they acquired foreign citizenship during this time without a special letter releasing them, they didn't loose their Polish citizenship. My question is if this is the case, what happens when that person reaches 50 years of age and is no longer required to serve? Does he lose citizenship at this moment, or does he get to maintain both? If he loses his citizenship, do his already born children also lose their citizenship, or do they keep it? Thanks!

I guess the age doesn't matter if you keep or lose Polish citizenship as long as you don't acquire citizenship of another country. The first point of the 1920 Poland citizenship act says:

"Art. 1. Obywatel polski nie może być jednocześnie obywatelem państwa innego."
(Art. 1. A citizen of Poland cannot be a citizen of another country at the same time.)

So the trick, as I understand it, is not to be a citizen of another country than Poland and if that's the case the age or children who had Polish citizenship don't matter. But let a lawyer shades more light on that ;)