Ultimately who knows, there was a lot suboptimal that night…still a F30 with a resultant 6 knot drop in Vref might have been worth having if the crew had really been aware edgy things were but they didn’t ( though the pre-departure landing check must have rung bells).
As you say there’s not much attitude difference between the two settings, must admit never had an issue with F30 in crosswinds…
FWIW as I mentioned upthread the whole subject of F25/F30 got a bit of a wringing out in this…though mostly in the context of contaminated runways.
BKK overrun report
Page 33 onwards and a whole annex to itself as well, Annex H…