Maybe this:i think I'm limited to one of the *sense since i am using wpa_supplicant for ATT Router replacement. Currently I am on PFSense 2.4 and using it as head FW, for my home network, i pass a static ip down to Sophos UTM and use it for additional protection. PFsense only acts as a router for ATT and internet access for my IOT devices where i dont want to block them from rules i run in Sophos and dont want them knowing about rest of the network. for VPN im using Sophos SSL vpn, since i only need it for few occasions im out of the house and want to check on network etc.
I did not see Vyos supporting wpa_supplicant, at lease from googling.