If you're feeling better without supplementing, I would pay more attention to that than lab testing.
Chasing biomarkers is likely a flawed strategy for most things, because what's in your blood one minute may be different the next moment. Plus, our bodies practice selective absorption. And, testing blood tells you nothing about
what's in your cells.
Things work in concert in the body. I recently posted in another thread the following link to a video where Dr. Michael Klaper wisely states: "In any complex system, you can't do one thing!"
So pushing one mineral up will have an effect others, as you alluded.
But, since you mentioned magnesium, I figured I'd link to the different forms of magnesium, in case you haven't already seen this resource:9 Common Types of Magnesium Explainedhttps://www.globalhealingcenter.com/natural-health/types-of-magnesium
Of course, whole, unprocessed foods are the best way to obtain vitamins, minerals, and phytonutrients. That way, they're in their whole package with all their associated complexes and cofactors. But, smart and appropriate supplementation may sometimes be required.
Anyway, that's great news on your improvements and almost being able to put in a full day. I'm definitely envious, but also happy for you and encouraged!
Wishing you continued healing.