I think I may have found another temporary solution to this problem. I have Bose QC Ultra Headphones and every time I started MSFS 2024 I would experience a severe drop in audio quality as hands free mode would be forced on.
If you go into device manager under System Devices there is a device called “Bose QC Ultra Headphones Hands-Free AG” (assuming other brands as well)
I just disabled this device via properties in device manager and restarted my PC and now my headphones do not switch into hands free mode when starting MSFS 2024. Also, there is no 30 second delay when reconnecting to Bluetooth like others have reported with different work arounds. When reconnecting my headphones, it is virtually instant.
I found this solution on the third page, second reply of this windows forum
EDIT: Make sure to restart your PC after disabling the “Hands-Free AG” device or it will not work. Also after windows updated to 24H2 it enabled this device so I had to disable it again.