On the subject of Montreal. Just a suggestion.
I see there is a Montreal feed dedicated to the de-icing frequencies that appears to be live at this time. These frequencies are not used in the summer and after a quick check of the archives I could not find any transmissions on this feed (some splashover).
The Montreal Center feed also includes 120.425, this is a Terminal frequency that is usually cross-coupled with 125.15 and 134.15, and is quite busy at times blocking out the Center transmissions. 125.15 and 134.15 are already on the Montreal Terminal radio which is already very busy with the other Terminal frequencies.
Any chance as a test you could remove 125.15 and 134.15 from the Terminal radio and remove 120.425 from the Center radio, then put 120.425, 125.150, 134.150 on the radio that is being used for the de-ice freqs.
Then on the Center radio add to the existing frequencies 134.400, 127.875, 133.225, 123.925, 134.975, 132.350, 126.575. This would give you complete Center coverage high and low in the Montreal area. (You may or may not hear the controller on 134.400 the RCAG is listed as Montreal but it's not near the airport).
Just as a test to see what it sounds like ?