When I started out, I did a switch from PM + MSM + D3 etc., directly to HRT. I kept everything else going but changed PM for sublingual/buccal estrogen. Then two months down the road I switched from pills to injections, later added progesterone and T blocker and all this time I kept very simple NBE program on the side which I started to broaden when I was +6 months in.
I started bovine ovary just some weeks before hitting ten months on HRT and so on, then added amino acids, milk thistle and so on later and tested a bunch of things which didn't turn out so successful and this is what I've been doing since. Right now I'm doing things a bit more simple than last year and hoping to simplify even more.
So my idea would be to start HRT, keep supplements to minimum, MSM+D3+Calcium is totally fine though and so are things like multivitamin, GABA etc., which are there as a sideshow, for health reasons and so on. Then once your body starts to adapt, you can broaden into more extensive NBE program. I wouldn't rush because I think its a good idea especialyl about breast development to let your body do the initial stages without overdoing anything. I believe its crucial for getting your development not go wrong. Also it seems that NBE starts to work the best once you're in Tanner four development. So no rush, listen to your body and let it adapt and slowly add stuff you want to do on the side. That way you can also easily troubleshoot if you get side effects from something.