That's true. But, there's the potential brought by the Lewis Yard (near Grimsby), which I wrote about a decade ago at
www.raisethehammer.org/article/2672
While simpler addition of signalling is what is needed, I observe that the newer 2015-built bridge over Centennial Parkway has lots of unused train lanes, built in a heavily masterplanned way to allow a nice 4-track corridor long-term.
The existing masterplans generally has plenty of modifications to switchwork, more track, combined with Lewis Yard, all of which can be used to turn the trains around easily, some of the morning bootstrap is stored there. The question is the "when".
Easier turnarounds (if CN is a bit reluctant to share) may have to wait until more spare train trackage eventually get built/extended to help deadheading from West Harbour to Lewis Yard. This benefits long term improved service towards Niagara Falls. And if you're deadheading to Lewis Yard even for a temporary hourlong idling or refueling, might as well stop all of 'em at Confederation. It's a 4-track corridor with only 2-tracks most of it, and a lot of the masterplans shows extra track being desired at least to Lewis Yard.
Maybe some train driver could chime in on the potential ideas how to extend hourly to Confederation in the natural progression (albiet feels tortise slow...) of GO.