Trial and error (and @eddiegrinwald has done some of the work for you) is going to be the name of the game. Finding high carb that works for you and slowly bumping up the sodium on your own may be a good path. I find that mixing flavors can occasionally just end up bad. Making mistakes with DIY is cheap, making mistakes with pre-packaged can get pricey. That said I do both because as has been mentioned in other threads, homemade can be a bear to mix at home where we have tools and contraptions, oh and TIME. On the trail, the premix stuff works better. Still not perfect, but yeah better in that you won’t get a bottle clogged with a glob of maltodextrin.