My pleasure, and great points you're raising. The 'be prepared to stop' requirement was one that CN applied under CROR Rule 103.1(f): "When advised by special instructions that rusty rail or other conditions may exist, occupancy of crossings with automatic warning devices must be manually protected unless it its known that warning devices have been operating for at least 20 seconds."
It was only two days after first CN Crossing Supplement was issued, that VIA amended the instructions to crews whom it didn't think were adhering to the CN instructions:
"In addition to the requirements of Rule 103.1(f), all affected movements governed by the VIA VENTURE EQUIPMENT CROSSING SUPPLEMENT must not exceed 45 mph from one-quarter mile of each crossing identified. Acceleration may only commence AFTER passing the one-quarter mile and after confirming AWDs have been operating for a minimum of 20 seconds. Note: The 45 mph restriction may not provide sufficient speed restriction to permit stopping in the event of insufficient warning time at the crossing. When encountering inclement weather or extended braking distances (e.g. rail contamination such as falling leaves), a slower speed may be required."
This additional requirement potentially made the situation worse, because there apparently are crossings that are well visible from far beyond the whistle post as operational.
I can't say whether CN has, or even offered to, adjust the times on its instrumentation because it has never admitted there is any problem, and that VIA has to amend its operations instead, in effect because it's their equipment on CN's infrastructure that in their eyes is causing the problem. The reason Grade Crossing Predictors came into use is that with uniform (i.e. 30-second) were resulting in drivers and pedestrians going around the gates. There have been no instances of non-operation, and precious few (CN Drummondville Sub warning times that led to all this) short warning times (SWTs) that it's all about CN claiming safety as their number one concern. Which of course it should be, but that doesn't mean that CN can't change its technology just as VIA has had to. Transport Canada could truly be the regulator in this schmozzle, but sure hasn't yet, if ever! Ministerial Order seems rather toothless or at least glacially slow in being moved along.