Next month I'm going to Bangalore again. Trying to avoid LH on the return (prefer UA as I can use SWU to upgrade from C to F). If I take LH, I do believe it is the "old business class" to boot for 21 hours flight time -- yech!!

The options are BLR-BKK on Thai Air with a one hour connection to UA (BKK-NRT-SFO). Or BLR-SIN on Sing Air with a one hour connection to UA (SIN-NRT-SFO). All things being equal I'd prefer SQ over TG, but I'm wondering which connection will have the least risk. Neither connection is technically "legal", but I won't have checked baggage so it seems reasonable.

My gut is to go thru BKK as I believe the walk is less (due to the fact the airport is much smaller). In Singapore, SQ and UA are in different terminals.

What I don't know is on-time stats and whether either airport has special "transit" rules that make things take longer (like having to go thru passport control again (which is slow in BKK) or some other nuisance.

Any thoughts?