Here ya go:
I thought I took screenshots later on at the 1d 19h mark, but I guess I didn't. Oh well I ended up going just under 1d 20h's before my battery finally tipped over to 90%.
Imo this is proof that my theory of "battery says 90%, could really be 81-90%" is true. There's no way my battery was at a solid 100% for almost 2 days straight. Idle or not, its not possible. So this tells me that it had to hit 90% finally after almost 2 days.
But yeah, battery life on this phone is excellent. Undervolting is really not necessary.