[dqv]

>My knowledge in telco and VOIP is very limited, do you know if there's any way to identify a number one has been forwarded to?

Do you mean like the calling party being able to find out what your burner number is?

I think that information could be revealed if you do a SIP refer. To be extra careful, you'd want to answer the call on FreeSWITCH/Asterisk and then bridge it to your burner number through whatever gateway (e.g. Signalwire, Flowroute, Twilio, whatever SIP provider you choose). The calling party will just see that they're calling your bastion.

It can also be revealed if you have the default voicemail set up on your burner, since a lot of voicemail systems will read the number out to the caller.