Not directly logbooks, but there is a case in which a pilot put extra time on an 8710. When the revocation trial happened, the pilot argued that since the false time was in excess of what was required, there was no harm no foul.

Guess how successful that was.

I'll stick to my guns. Keep track of porcupine in containers in a special column or in the remarks. Put it in the PIC column without further explanation and you're looking at a potential 61.59 violation.

I've heard the "napkin" nonsense many times. So far though, I haven't heard a story about a pilot who, after an accident and in response to a request for his logbook, handed the inspector a shoebox full of napkins and stray paper. I'd almost bet we'd see some very interesting language about "in a manner acceptable to the Administrator" (61.51(a)) in the NTSB decision upholding the certificate suspension or revocation.

Yes you are only required to log for currency and qualification. But that does not mean that false entries above and beyond that are a-ok.