I think your link refers to the FLR(M) process receiving exiting the UK during the application review, not the initial leave to enter partner visa process and entering the UK. I’d imagine that’s why I have an email from UKVI directly stating that it’s fine to enter the UK on my second passport?
Can you post the letter? As having the hard copy available as a digital download could be very helpful for others? Black out your name and details of course.
Yes, the link I provided was for FLR(M), however, the UKVI documentation states in ALL application types that you can only have ONE valid visa for the UK at a given time. An application after a previous application will over ride the original. So your visitor visa stamp supercedes your settlement visa, as you applied for the visitor visa AFTER your settlement visa, invalidating your settlement visa.
Like I said, you may not run into any trouble. But I stand behind NOT recommending other people have that hanging over their head. Most of us didn't want to do ANYTHING to jeopardise our visa status.
I have a colleague who's husband just received his Indefinite Leave to Remain. She WOULD NOT believe me for the last few years that her husband COULD use the NHS. She did NOT want to jeopardise anything. Even though it was 100% legit.