So I've made a few loaves using my sourdough starter and a small qty of dried yeast (1/4 tsp or less). Generally the flour is a mix of King Arthur's bread flour and whole grain whole wheat. I'm fairly pleased with the results and the family is eating them up. Pure levain hasn't worked so well, so I like the slight jumpstart the commercial yeast is giving the dough.
Looks nice, so long as the family likes it, no need to change what isn't broken.
There are many different ways to skin a cat, so the saying goes. You're making an effort and producing what looks like a tasty loaf of bread. Keep on keepin' on, I say.
Be careful!
I contaminated my starter by accident with commercial yeast.
Broke my heart to start over...
Good reason to save a backup of your starter (there are directions out there to dry some for long term storage). Then when something goes haywire you can get back. I need to do that myself!