As a follow-up we had first hand experience on a charter in 1997. We ran a limited people charter after the Rotary run. This was 497 leading, and 484 as the helper ahead of the Caboose. The plan was to continue to Osier, turn on the loop and make a westbound with a mid-train helper back to Cumbres. When we got to the big loop across from Osier there were track crews clearing the mainline with a back-hoe, and another group trying to clear the loop track.
So 484 tried to plow through the loop, using the flanger plow. Neither of our engines had a pilot plow up front. This plowing worked well for several hundred feet, then the engine derailed, and had to be derailed before we could continue. So not being able to turn we went further east to Rock Tunnel, but first swapped engines at Osier Siding, putting 484 on the front with all the snow on the front of it. Then the whole train had to be backed to Cumbres with 497 running tender-first with the train in tow. Footage of the 484 plowing with its flanger is in the video "First Train To Toltec" Les Jarrett and I did the charter, and he got footage. When the problem was known I didn't carry my gear to the front of the train from the caboose but Les did. Its some dramatic footage with slipping and so forth. Here is the YouTube preview which doesn't have any of that footage, but does show the aftermath with all the snow on the front of 484. So that was first-hand experience with these pilot flanger/plows for me!!! Earl might be able to tell us more as he was running 484.
Greg