So we "lemoned" our last vehicle, right before getting the '21 Suburban. Similar to you, ours was in the shop for 35 straight days. It was finally fixed, but the confidence was broken, and I had also decided that the vehicle was a bit small. Unlike you, we had no issues with the company - the whole process took about 3-4 weeks (they didn't fight or give any grief - assumingly because the law is pretty straightforward). I cannot understand why GM would fight it since the 30 days is crystal clear in state law ( not sure every state but seems like most) , and they cannot win. All they will do is burn cash for the lawyers, and waste time.
In the end the buyout offer was exactly what the law said it should be - every dollar we spent (including a rental we needed due to the loaner we had being too small for a family trip) minus the usage fee. They also offered a cash payout where we keep the car. We almost took the buyout, but when I realized we would be buying a new vehicle I quickly changed my mind and took the payout. The payout was maybe 1-1.5k or so less than what they buyout would have left in our pocket, but in our state you do not pay sales tax on your trade-in value. So I paid off the trade-in, and used it to offset about 4k in taxes on the Suburban.
I suspect 2020-2021 will be record years for lemon vehicles- due to parts shortages and wait times in the service bay...