Went with the giz method. Everything very clean. Brand new tank base and coil. Real resistance triple checked (two devices and a meter) for same or within reason same resistance all three. I could not get raw ohms to remain stable. Tightening, loosening. Tightened down more than my comfort level. Moving within 0.001 up and down from most stable number. Got a lock for about 10 seconds and used that numbrer. Final number 0.003 which seems to be a common range for 250 devices. Shave a hair off for safety margin inputting 0.00285. Vaping in temp mode beautifuly now even on SS nothch coils. Seems liks it reads cold ohms a hair low so I may fiddle the mod resistance input a bit to get it closer but otherwise its like a different mod.
Thanks for the tip