Fuse/Relay Wiring

I've started wiring up the Relays and Fuses for my power supply and I missed my boost control solenoid. (I also don't have any slots left for another fuse inside the fuse box)

Can I splice into the idle control solenoid power supply wire (18AWG) and let them share one fuse?

I will upload a picture of my power supply design and picture of my fuse box wiring so far if someone could judge it that would be greatly appreciated.

Here is my diagram and Fuse/Relay box so far.

You could also run both the idle and boost solenoids off the ECU circuit.

Thanks David. Good to hear that I have options.