Crank scrapers or plate...?
adjustable PVC??? Shiii, I actually believe that those work! .... Scraper will accomplish what by itself?
Adj pvc is def a reasonable idea, especially once we start screwing with motors away from the stock stuff the factory pvc was setup for.
In the 70's Chrysler did some dyno work on Hemis and found above ~8k rpm you could pull the pan off and not make much of a mess. Nearly all the oil was flying around and stuck to the crank/Rods or in the rotating assembly's windage vortex. Windage tray by itself did very little fix the problem, created more of a wind tunnel effect. Crank scrappers fixed the problem. This was done developing the pro stock motors at the time.
Think of a crank scrapper like a lathe (crank) and cutter bit (scrapper); way closer to the crank is obviously gonna remove more of the oil hitching a ride on the crank.
Classic windage tray only catches the stuff already flung off, helpful for sure but not the same by any means. In theory it catches hanging oil before it contacts crankshaft again and slows crank down. But reality is, if the oil drop or "rope" is in a space that it can be hit by the crankshaft, it BETTER not be hitting the windage tray- or your crank and windage tray are about to have an interference fit. In a moving vehicle it's better at controlling splashing back upwards towards crank from the sump.
Don't get me wrong-I run both inside of a milodon road race pan. Both have their functions and compliment each other. I'd probably have to put the car on its roof or run it without the drain plug to starve it of oil. Sounds like windage trays have worked great for you, so keep using them! But that also doesn't discount crank scrappers also working, fair enough?