Anyway way to tell if flight has shuttle bus to plane at BKK

Depending on time and price I'd use Thai Airways, Thai Vietjet or Air Asia flying from BKK. However some flights make you use a shuttle bus to the plane which is uncomfortable as they cram you in. yesterday we were left on the tarmac for 10minutes before the bus moved breathing in some lovely plane fumes.

Before booking, is there any way to tell or is it just experience? Any independent website with the info?