we would like to suggest to add the following feature in the GUI
for Routing Services, with FRR, you can create BGP neighbors in the GUI
however for the options, that you can configure per Neighbor, the option "local-as" is missing,
which allows you to override your local AS number for this specific session with that neighbor
e.g.
conf t
router bgp 1234
neighbor 1.2.3.4 local-as 12345
exit
Please create an issue here:
https://github.com/opnsense/plugins/issues
Did you see this checkbox in neighbors btw:
Enable AS-Override