Yes, 50 is signal quality. I am sure I had multi path before. Antenna has a rotor so there was 2 intermittent fair signals but would come and go depending on the wind, fog etc. We gave up doing reliable recording of our favorite shows on 40 for a few years.What does "50" mean? Is that Signal Quality? Maybe you had multipath when KTXL was on RF 40 but you don't on RF 22. Your description of your location sounds like that is likely. 10% power sounds like really low power but they're running 100KW still. For all but the fringe areas 100KW should be more than enough power. I'd be curious to hear what happens when they increase to 1MW. Please report back.
You might look at your Rabbitears report to see the Noise Margin in dB then subtract 10 dB. If it's 20 dB or higher then higher power probably won't do anything for you.
I have been watching the sig level and it reliably stays above 50... I am very pleased! Will report back when they bump up to 1MW. All other channels come in above 50... Heck 29 is now a boomer hahahaaa!
Over the years I have perused this forum for any news of others struggling with 40... Did not seem too prevalent. My property is in the worse spot for Digital signals coming from Walnut Grove anyway. Couple the hill in the way along with tall dense trees and I am lucky that we even get OTA TV.