I have a trip booked soon to visit my homeland. Upon return I will be arriving at swampy [Eva Air] and transferring to Thai to end destination CM. Being Star Alliance my baggage will [hopefully] go straight through. I recall some time ago in a post someone described a way of escaping the chaos  at BKK Immigration. Is there an 'In Transit' international > domestic? Is it the same route as the international > international?

 

Informed comments would be much appreciated.

Assuming your bags are checked all the way through to the domestic destination you will be following the signs to the domestic transfer area and there is a small immigration maybe about three desks. Normally you pass through this quickly unless a Chinese tour group is front of you ( happened to me once) and it' quickly turns to chaos. You are then in the corner of the airport with all the TG and PG domestic flights. When you arrive at your domestic destination you have to follow the other international passengers and go through customs with your baggage. 

I have done the EVA (BR) international to TG domestic transit.  EVA did check my bag all the way through, but I did have to get a TG boarding pass at the domestic transit section was was about a 1KM hike from the BR gate.  Hopefully you have at least 90 minutes as you have to clear security again immediately after getting your TG boarding pass.  As stated above your bag will arrive at CNX in the international area.