I was halfway through your post and was about to ask what you already answered. I always that it was done manually so you could note the settings.
I always thought it was done manually as well. My first Oled was an LG 65 inch in 2016, in fact the first flat screen 3d Oled. It was calibrated by Vincent Teoh. He input all the settings manually after calibration and then sent me the settings via e-mail latter that same day.
My current 77 inch G2 couldn't be calibrated by Vincent because he has stopped doing it for a living now. So i had it calibrated by Steve Kemp (
https://www.displayandsoundcalibration.com/). He is the ISF instructor for the UK and for some parts of Europe.
During his time at my house he told me that should i ever have to do a factory reset, all the settings his software would be uploading to the tv will be lost and it would need to be re-calibrated. I asked him why, as Vincent had sent me all the settings. Steve said with modern tv's that simply is not possible.
Yes, i have access to basic settings, but not to any HDR settings and not to multiple setting for all input sources at the same time. This amounts to 10's of 1000's of settings, 99% of i have no access to at all.
When the calibration was done the upload from his laptop to my G2 took nearly half an hour, so i have no reason to question what he said lol. He did also tell me that no firmware update will affect the settings..............................thank god
Calibration and the complexity of tv's has come a long way since my first Oled in 2016.