This. The exact seat that Norse sells as Premium. Misleading really

Yes & no. While I can't vouch for the soft profuct, the seat pitch here is 5 inches longer than your average premium economy seat. The recline is also double that of regular premium economy. But yes the second leg is a kicker

And apart from the fact you are connecting in India.

Do you also need to get a visa? If so, that would be an additional pain.

No visa required if you dont leave the sterile zone. It may take long for additional security to get to international departures but its doable

Anyone flown the A321 from DEL/BOM to BKK. Is that a normal seat that you get in economy labeled as Business (like European business) or does the seat provide more width and legroom?

The business class is wide with more legroom.
https://www.aerolopa.com/6e-32q-3
The other A321neo types do not have business seats.

I'm doing BKK-BOM in a few weeks. I'll report back.

I have flown Indigo and would avoid for long-haul, they do not have lounge access, no hot food just hot water on top of instant noodles or instant food packs. They are ok for internal domestic short-haul flights where you can “buy” double XL and fast forward (priority check in, baggage etc.). Better to fly angled flat or lie-flat with other airlines , not sure how they are getting away marking these as business class!! Also, avoid transiting via India - security is difficult, they will make you take out all cables, adapters, laptops, AA batteries (apparently only 2 allowed), all electronics and you go through security even for domestic transfers! Also Indigo uses a different terminal in Mumbai, Delhi and even Bangalore, they often skimp on gate boarding - take you via a bus that is fully loaded to capacity, and then climb stairs. Definitely not a “premium” offering!! If you have to change terminals, then you have to go outside and look for boarding an inter-terminal shuttle that runs every 30 minutes. Even Air India has dedicated lounge and they will fast track you through while transiting in business class (but Air India has its own problems as well!).

They give you hot food, lounge access and drinks on the 787 legs.

"Plane and crew operated under lease from Norse."

If IndiGo (6E) uses such leases because they are just getting started, perhaps it's best to wait until they are more established.