It isn't really a "solution" but perhaps tweaking the pre-clearance area to have a snake line for the non TSA PRE travellers could help some. YWG could also see if they are allowed to undertake a bit of a public awareness campaign in the community on the Nexus program. Honestly the $50/5 year pass is really worth it even if you only travel a couple of times a year.
For those that don't know Nexus gets you streamed into a different screening line for both US Pre-Clearance and the general departures side at YWG.
On the US side anyway you leave all your electronics in your bag, including your laptop, and you don't need a special laptop bag either. You keep your shoes on and your carry-on approved liquids can stay in your bag. Most of the time you walk up to the security screen, place your carry-on items on the belt and just walk through the metal detector. It really is that simple. It is also common that the people in those lines have taken time to make themselves aware of the screening process and come prepared to make it go quickly.
I know us Nexus people like the be all "fight club rules" and not really talk about it to keep out lines short but we will consider you friends and let you in the know.