@metisit Still no progress as I am facing some other issues here.
Honestly I start thinking to revert to normal static IPSec, but the fact that I won't have to step in in the middle of a "crisis" and let BGP do its job, keeps my faith to this configuration.
As soon as I solve the other issue that I have, I will give it a shot.
According to Netgate support, what I mention at the beginning is totally reasonable and can happen.
I'll keep you posted.
Chris