Let's set the record straight here:
1) There is a transfer desk on the international arrival levels for domestic flights to select airports and CNX is one of these airports. So long as your bag is checked through to CNX you will not go through the regular immigration lane to streetside. Rather you will pick up your domestic BP on the 2nd (arrival) floor at the confluence of concourses A/B/C/D and go through Transfer Immigration there. You will pick up your bags and proceed through customs in CNX.
-All arriving passengers into BKK go through immigration whether it's ending up streetside through the main areas or transfer immigration when proceeding to a domestic flight. Customs can be dealt with at select airports which have these facilities and CNX is one of those.
2) When you check in with EK show them your separate itin to CNX and ask for your bags to be sent to the final destination. I know TG interlines with EK and see no reason why the inverse would be any different. Also, stop being concerned about TG vs TG

. This is all TG. Don't confuse anyone with extraneous information.
In the extreme case where EK says they cannot interline your bag then you'll be pressured for time but it absolutely can be done. Two hours is a legal connection if you
need to get your bags in BKK. You'll need to go through the regular immigration lanes then get your bags. Customs is a breeze. Go up to the 4th floor and checkin. Domestic security is a breeze as well.
That being said, going through all this will be tight. The cutoff for domestic check in is 40 min IIRC so any delay in your incoming flight or baggage delivery can compromise the connection.
But, and this should be noted, you should have no problem getting your bags sent through to CNX.
[KVS Availability Tool 7.1.7 - Reference: Minimum Connection Time [MCT]: BKK/EK-TG]
Code:
DD DI ID II
STANDARD: BKK 075 075 075 075
EXCEPTIONS:
A/L
-ALL- --- --- 075 075
TG
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