Bit of a pet subject of yours then, dill?
Like many people working in this region, I never....ever...know my holidays two months ahead.
I'm also never....ever...looking for flights that leave after 3pm.
For earlier flights there are better, cheaper options from Suwannapoom, which don't involve a 1 hour bus ride. Vietjet in particular.
BTW...skyscanner prices shown are NEVER anywhere near what you end up actually paying after add-ons like baggage and, oh yeah, an actual seat to sit on.
*sheesh*