I shouldn't have been so lazy before and checked. Apparently when you return your pension is adjusted to the prevailing rate. I am not sure how they determi e residency for pension increase applicability but if it is aligned with tax residency then keeping a home and staying there for a limited period each year can qualify you
I think you make a really important point. Over 10 years you can lose 30-40% of your purchasing power to inflation, making a move to thailand a non-viable long term solution if this is your only income. Do you know if you move back to the uk will they readjust your pension to the current minimum or are you still stuck at £920 as your base?