What are my options?

I have a 2023 Yukon Denali with the 6.2 and have been working since June on an oil consumption test that did fail and the motor has scored cylinders. Been back and forth to the dealer numerous times so they can run tests that GM wants. It’s now been in the shop for 4 weeks, with the heads off and now just sitting outside with a cover over the motor while the dealer waits on GM tech to give them next steps. It’s been a week and they still haven’t heard from GM tech. Here’s what’s been done:

1. Spoken to manager at dealership (said they have to wait on GM tech and nothing they can do)
2. Spoke to warranty guy at dealer and same answer
3. Dealer has spoken to district manager and they both are advocating for a new motor but said they can’t make that call and have to wait on tech
4. Opened a case with GM customer service and got the same answer everyone else gave me
5. Escalated to GM’s executive team and they have contacted dealer but nothing else has been done
6. Contacted an attorney and they said they can’t do anything because it’s not like they are refusing to do the work and are still “troubleshooting”

Where do I go from here? How long can they just hold onto a vehicle and not give a direction on where they are heading? I do have a loaner but it’s a 4 cylinder Subaru.