I developed an electronic circuit I called the IATimer that starts out
"not there", then gradually ramps in (adjustable ramp time and final offset value) to an offset of the IAT Sensor value for advanced/retarded ignition timing. A similar ramp circuit could expedite the ramp-in of the coolant temp. This version definitely requires electronics & programming skills. Not sure how to do it with junk yard parts, though. I'll give it some thought.
I’m not smart in electronics but was thinking in the same line but for the o2 sensors, showing it’s already in the warmed up loop. But I can see the temp sensor needs what you say too. My foot can keep it running till it’s really warm.