best fix is get the wood bed home
put in oven or on hotbed at 180f for a few hours to slowly drive some of the moisture out.
while warm from oven PAINT IT seal it

i did this just because i know what wood wants to do when i got the printer going on 5 months even better then the day i got it (the low temp even heat bake to some of the org bowing out apx 3mm)
now i say from point to point no part of the bed is off by more then 1mm