I do not think the onboard tuner is very accurate to begin with. But it is better than nothing, for sure.
I always check fine tuning by ear, using harmonics, even with my TC poly tune which is super accurate. And I check tuning every time I pick up a guitar. Amazing how often they go out a bit...
What did you use for your buttons, and where did you get them?
I am looking for similar buttons for a 2017 552 12 string with stock Taylor mini tuners.
Are yours a nice fit on the Taylor mini tuners? May I ask where you found yours?
Cheers
Paul