Both v3 and Black are really newly released so it’s a bit early to get many experiential answers to this.
It will be interesting to see people’s reports over the next few months.
I didn’t get any gut issues with v2.3 so although I’ve tried Black and still get no gut issues, my experience isn’t of much help to you
I think v3 has been formulated to be smoother and with no artificial flavours, and with probiotics in part to try to reduce gut issues. I don’t know this for sure I’m just guessing.
As for black, it has slightly lower fibre and no oats and no sucralose - so if any of those are the cause of your gut issues then black may well solve it. But then some people get bad guts on a high protein diet, so we may well see some peoples problems solved by Black Edition and others getting worse!
I hope people feed back on this. It’s a good question and it will be interesting to see people’s verdicts