1997 Chevrolet Suburban, Relay system

Hello everybody, I’ve recently acquired a 1997 Chevy Suburban without a factory alarm i currently only use the truck only for rural delivery services, i wanted to limit the constant on and off of the vehicle in between stops after searching around i came across Secure idle meant for police vehicles and i got me wondering if a toggle switch and relay or relays could be wired that when on it’ll allow to the vehicle to idle with the key removed and killed when brakes are pressed. This is what i’ve figured so far with two relays and a toggle switch. First, one side of the switch will be connected to the ignition (pink in my case) then the other side is connected to pin 86 on both relays. Secondly, pin 85 of both relays will be connected to the positive brake wire. Thirdly, pin 87 of both relays will be connected to the RED 12V+ wire. Fourthly, the first relay will have pin 30 connected to the igniton wire (pink) and to the 2nd ignition (Dark green). Lastly, the second relay will have pin 30 connected to both oranage and brown accessories wire. Thoughts?