I have wireguard at present to traffic all my lan clients. The issue is there may be one or two that i'd like to keep off wirguard. Basically I want one device going through WAN without going through wireguard. it is my htpc and my vps cant handle the monthly traffic of netflix. I would like to have access between the lan and that device internally. not externally.
You should be able to use the FW rules to do this.
I presume you have a rule on your LAN interface that states some thing like
Source LAN, Destination any, Gateway Wireguard
Place a rule in front of that which states
Source HTPC, Destination any, Gateway WAN