Gamerule to make Strong Seed more frequent/to turn it off.

I know some people aren't a fan of the implementation of the Seed is Strong submod (giving specific houses custom portraits Reyne/Arryn/Stark etc.) and some really love it. I'm one of the ones that really enjoy it and now that the mod is most likely not going to be updated again it would be nice if we had the option to make the portraits happen as frequent as they were with the mod or for people to have the option to turn it off if they want to. Currently specific house portraits have a rough time standing the test of time and many will be gone within a half a century if they are unlucky