This is why I said "my" OP, and not "the" OP. Either way, not sure how the comment was helpful.
The problem is there are so many posts of saying to do this or that, and everyone has their anecdotal "proof" as to what is best. Even trying to look at the science behind the chemicals can support or go against what people suggest. Yes, I am trying to learn and I don't feel bad about it, and have never said anything to suggest that. I'd rather hear why switching back and forth (other than the cost factor) is actually a bad idea since Dex 3 and 6 are supposedly compatible, instead of how I miss the mark on being competent on simple concepts. This I already assume is true, which is why I found this thread in hopes to grow. Apparently others still have questions, too. I'm grateful for all the help people are giving.