https://docs.opnsense.org/manual/how-tos/transparent_bridge.html
Wifi calling doesn't work through double nat..
So anyone with a consumer 'orbi', 'google', 'linksys', 'eero', etc. mesh setup who then for some reason wants to put a better router in front will then fall into the double nat issue.. and then have wifi calling issues; ie the phones will show vzw-wifi, att-wifi but won't actually be working (some androids seem to be better at this than others.. :dunno:)
having a transparent solution would resolve the double nat issue and all that comes with it..
(unless you had a three legged device.. usb eth adapter, wifi etc..)
Anyway.. having a console menu option like vlan, wan, lan, for creating this bridge.. etc.. might be a good idea.
My 0.02