I can speak from experience from last week on the track.
My IAC coolant points failed
The hard line in too it to the IAC come loose so made a little of a mess.
I'm running a link ecu aswell to fix my leak I removed coolant running thou the IAC, idle is better then before so I guess my wax valve was faulty. Cold start still works quite well good tune helps.
To bleed system with no bleeder I jacked front end up so radi was highest point seems to have bleed correctly.