I read somewhere that you should never double a recipe. Something about it not "rising or reacting" the same way as the original proportions??? Has anyone heard that or have any opinions on that??

I double all the time cake and cookie recipes and triple cake recipe sometimes without any problems

Some work and some don't. It's that complicated when you are using scratch recipes. For me, it goes back to what I always do... Take Notes. If you do, then you can research what went wrong, adjust the recipe, take notes, and try again. Make sure you start with your favorite, balanced, recipes so that you have a good base. Sometimes I have to make them several times to get it perfect. I think this is another of those cases where some people don't want to go through this with scratch recipes. But with notes and some diligence, you will have this recipe forever in your repertoire.

Its ok with me ,
I do it all the time

Its ok with me ,
I do it all the time

If the base recipe works, then you should have no problem scaling up. But your calculations must be correct so watch that math!

The only thing I have trouble doubling is IMBC. Everything else works well doubled.