Not able to get my head wrapped around your issue, but just wondering, you understand that with the pump in the gasser's carb, you're able to put the tank about anywhere in the plane? For that reason, many put them on or maybe just ahead of the CG/wing tube, leaving the area in back of the firewall wide open to mount the throttle servo about anywhere pretty easily. Fuel tank on CG means no/minimal CG shift from full tank to empty.

Picture stolen from somebody, not supplied to promote Z bend at carb arm, but to show potential for "less than straight" pushrod from servo to carb arm. It doesn't necessarily need to be straight.

Apologies ahead of time if I've completely misunderstood your question. -Al