I thought the Tesla system worked a little different for voluntary termination. Normally it is 50% of all remaining payments but when the going is good it does appear that Tesla factor current vehicle value in to the calculation in a similar way to handing back a salary sacrifice lease if you leave the company.
This has led to people seeing massive swings in termination value based on the used value of their current model but there have also been times where people have seen reduced termination values coincide with when Tesla are looking to boost new sales. There are tales abound of people getting out of leases for free in the post covid recovery, we certainly walked away from our M3P with only a ver modest payment at 18 months old on a 4 year lease.
Sounds like right now they are just going for a straight 50% of remaining payments assuming a monthly payment around £600pcm