OP, if your spouse is looking for a supportive recovery group that is not religious (ie, AA) and scientific based I suggest he look into
https://www.smartrecovery.org
It's based on rational emotive behavior therapy and is all about personal choice and responsibility. There are no sponsors and you are not castigated for slipping -- you just pick yourself up and keep going.
It sounds like he's in the pre-contemplation phase; he's exploring the idea of stopping his drinking but is still ambivalent.
I'm not sure about the motive for showing you his BAC every day -- perhaps he can keep a log of when he's feeling urges to drink, triggering situations, etc. and you can work together to mitigate.
I know this is somewhat rambling but I wanted to give you information that there's more out there than AA. Smart has online meetings, forums, a 24/7 chat, etc.
Good luck with your decision. It's hard. Very hard to quit.