Because of the amount of travel you do
@Pe***
, I would suggest you get a year-long, multi-entry Non-O visa based on marriage from a thai consulate nearby or back in the UK.
That visa is good for a whole year from the date it's issued it's unlimited entries with each entry to thailand getting you stamped in for 90 days.
It's very easy to get from the thai consulates in Savannakhet Lao, Ho Chi Minh City Vietnam & Seoul South Korea.