Easy process transfering the stamps to do self at immigration. .
90 days you can still do online with old passport number, just make sure you have it correctly updated at immigration office before you aplly for your visa extension.
https://chiangmaibiking.com/chiang-mai/
Flat tours for all ages, small groups , bigger groups on request.
Give them a call first as the owner might be out on the bike if you just walk in.
Good luck
i came here on a Non B , after 90 days i did a border run , got a new Non B from Mae Sai and that one is transferred already 2x to my new passports.
Like i said best to go to Immigration to be sure and don't rely on anyone else but your self.
Here in Chiang Mai they are very strict about the tm30.
You can just walk in at Immigration with your passport and tm30 after staying at another location in and out of Thailand.
Go to the designated desk and tell them to update.
That's all, no agent needed.
Most likely you not in the tourist business as numbers are up compared to last year which was slow after Covid.
Before Covid numbers were going down a bit but still booming business for many operators.
You can always plug it in to your computer if you have one and copy files there first, then connect your new phone and copy then back so you have it on your phone and as back up on your computer.