I’ve been calibrating my appearance for a while, but now I’m going to A/B test various things based on feedback from people around my and self-reflection.

There are gains you can get by A/B testing but there a lot that you can't analyse that way. You can't easily A/B test whether growing bigger muscles will benefit.

I think that's many significant factors. it takes a lot of work to make deep changes. Don't just go for interventions that are easy and therefore also easy to A/B test.