PBGC premiums for 2024 with a lookback

Starting a general discussion rather than a specific question.... As we know returns during 2022 were bad, 2023 is still iffy but not exactly great either....Which means that PBGC premiums for 2024 using a lookback (1/1/2023 for BOY vals and 12/31/2023 for EOY vals) might be a quite unpleasant surprise especially for plans that started 3-4 years ago and are just hitting the "vested" point.  So, I am curious what others think about the "opting out of look back":

1) Is it realistic for PBGC to approve?

2) Does the 60 days advance application to PBGC mean October 31st deadline?

3) I realize that for EOY val date it is not practical (valuation results are not available until 2.5 months AFTER the premium is due) however:

1. I believe PBGC filing can be done on an "estimated" basis with the subsequent "true-up".  Yes, it is an additional work but might be worth it?  Or not?
2. Is it likely to get approved by the PBGC?
3. Has anyone ever done something like this?
4. Are there any other considerations or concerns?

TIA.