I have a filter on the engine that does this for me when the engine is running. Not sure how much difference draining the oil when warm would actually make. Haven't found any significant amount of sludge in ~650 hours either, so who knows?
There's a lot of contaminates in used engine oil that the filter does not catch; it's not just particulate contamination to be concerned with.
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I think I remember the hot oil change being taught as a "best practice" in A&P school, and not a requirement.
The Sikorsky CH-53E, S-76, and S-92 maintenance manuals, the Bell 412 maint. manual, the P&WC PW210S and PT6T maint. manuals, and the GE CT7 maint. manual (I think Agusta, Eurocopter, and MD are similar, but it's been a while since I worked on those), all
require a hot oil change as part of the required maintenance after a suspected or confirmed case of oil contamination, to include popped filter buttons and chip lights with chips found. They
do not direct a hot oil change for
scheduled oil changes; in fact, I've never done a hot oil change on any helicopter as part of
scheduled maintenance - I've caught them still-warm a couple times, but never hot. At their formal engine school (Arriel 2S1/2S2), Turbomeca
recommends a hot oil change for all oil changes, but only
requires it for suspected/confirmed contamination.
Granted, these are turbine engines and helicopter gearboxes, so the info isn't a direct transfer to the RV/GA world, but it does help illustrate the thought processes of OEMs.
FWIW, I do hot oil changes in my vehicles, and I would do hot oil changes if I were an RV owner/maintainer. It's what I was taught as a kid and a young adult, and I personally believe it's a valid technique.