You mean them giving a Battlefield Effect or acting like a Visit Site?Quite right! Forgot about that. Still, per tech unique orbital relays may be fun. Maybe they create better op strength, cloak redeployed armies or buff them, or allow for special actions in zones where they are present?
That might indeed be interesting. If the Voidtech Relay gave Fast Movement (accounting for the turn the unit is unable to move further), it could easily replace that opeartion.