the valve you have mentioned is the 3 pin green idle up valve aka rotary solenoid in toyota speak.
When I wire up a BT the ECU does not have provision for a separate "vacuum leak" valve to compensate A/C load, if you have correctly wired up the ACT and AC1 signals the rotary solenoid on the manifold will control it. Power steering load maybe compensated from a mechanical valve on the rack valve body like the ST and also self compensating (Ive seen it - the ports would be blocked on the vacuum pipe manifold)
The usual mistake (as I see) happening with 4throttle conversions is that people connect both brake vacuum ports to one common pipe and then a one way valve, it should have 2 one way valves then one "TEE" piece. To prevent vacuum loss in the manifold