Low oil pressure makes me nervous

I purchased two different types/brands of oil pressure sending units on E-bay (not installed yet). One of the sellers claims his sender corrects a OEM defect where the oil pressure reading is different, depending on if the gauge is rising or falling. If true, that might explain why my gauge was reading a little higher when the oil was warm after re-fueling (after restarting-gauge reading more) and a little lower when starting cold and then running the motor continuously until warmed up (driving without stopping-gauge reading less).

I was finding it hard to believe that after a ten minute fuel stop my oil had cooled down enough (and thickened enough) to raise the oil pressure a measurable amount.

from ebay web site:
Patented design corrects a systemic flaw: If your oil pressure goes "up" to say 60 Psi, the original senders will show a different reading than if it comes "down" to 60. This re-engineered sender correct this problem. Accurate at all times, unlike sleazy imports, or even NOS! This is as good as it gets!

Mopar: Oil Pressure Gauge Sending Unit 318-440-426 OEM Charger Dart Cuda GTX R/T | eBay