As far as I know (and it is not much)
Just one time AY+QR route HEL-DOH-BKK experince and I got no worries at HEL airport though cant't remember weights exactly. Over 23 kgs anyway?
The IATA rule goes by the most significant carrier for your journey. But it has exeptions of which I am not too sure.
You didn't mention where in SE Asia you are flying to?
For example:
Distance HEL-DOH 2730 Miles
Distance DOH-BKK 3285 Miles this applies as most significant carrier
or
Distance HEL-DOH 2730 Miles this applies as most significant carrier
Distance DOH-DEL 1596 Miles
More seasoned flyers, feel free to correct if I'm mistaken