Lounge access in KTM during transit?
 

We (me OW Emerald, two family members both OW Sapphire) will be transiting KTM on our way to Bhutan, arriving on QR and continuing on with Drukair, both in Economy. Separate tickets means we have to clear immigration and go landside to get our bags, and it's not clear to me whether we can still use our QR boarding passes to gain access to the lounge after checking in again and clearing security. Does anyone here happen to know, ideally from personal experience?

JonV welcome to the QR forum. You may find the QR dashboard a useful tool.

Normally airport lounges are departure lounges for the use of those departing on that airlines. or alliances (Oneworld), flights. Drukair is not even an associate of QR so there should be no access.
The Executive Lounge that QR uses appears to be a third party lounge.
Yu will have to rely on ehatever lounge access Drukair provide.

You can do an airside transit at KTM but going landside might just be a bit easier. Lounge in KTM is operated by Radisson and accepts all kinds of cards and also available for purchase. Based on the tickets alone you will not get access.

The Radisson Lounge will not provide access based on an inbound ticket. If you have any status on Druk, that will be the only way to get access via the ticket.. As others above have mentioned, you can buy access to the lounge, although it is not much to write home about but atleast the bathrooms are clean :-). I think the price of purchase is $45 or around that amount per person. How long is your transit.