United Award Ticket Business Class to Mumbai Mixed Cabin

Pointify is tracking this dispatch for the points-and-miles community.

I was able to find an 80k Miles Award ticket IAH-LHR-BOM. IAH to LHR is Business class while LHR to BOM is Air India Economy. Is there any way to upgrade the AI portion to business class without additional miles or at least be on standby for it? It shows fare class of X for that segment. I can find other dates / airlines business class all the way there for 80k but they add 7+ hours and multiple stops to the itinerary submit