Sure, google provisions (maybe add the word bitcoin).
And taproot was specifically constructed so that solvency proofs could be more private and efficient.
I wouldn't actually put that much stock in professional auditors. Having deal now for a few years with a skilled conman in court and his professional support, it's clearly possible to get "reputable" professionals to attach their name to all kinds of sketchy shit. The conartist just needs to put up a maze and tire them out, and give them enough 'proof' that they'll have plausible deniability when it goes wrong. It's only any better when there is a long history of failures such that the auditor knows a reasonable bare minimum that will be considered competent for them, and we're not there for cryptocurrency (and even if we were it's still a weak guarantee).
So for example, I saw Wright fool professionals by simply making a pile of backdated accounting records and pointing people to addresses in block explorers. The professionals aren't going to do document forensics to figure out the docs were backdated. They're not going to think carefully that an amount paid TO an address with your taxid in it doesn't mean you own that address, and so on.