Thanks for your reply but your information does not agree with my experience or I did not fully understand your reply.
You wrote: "There is no US Letter Borderless printer selection from the Document's Printer selection."
That is now what I see. In the panel, Document->Document under the heading, "Printer & Paper Size" I see two drop down menus, one for the printer, set to "Canon TR8600 series" and the other to paper size, set to "US Letter Borderless". This option is one of many predefined borderless options that come with the printer driver.
You wrote: "That said, selecting that custom page does not change the displayed margin settings on the Documents panel. One must deselect header/footer, and reduce all margins to 0 in. At this point, you can press shift+cmd+L to toggle the Layout view and no outline of the document will appear indicating the absence of margins."
I wrote: "This is with all margins set to 0 in Pages as recommended...". These were the previously posted recommendations and I followed all of them. I have tried both turning on and off the various document components as well.
You wrote: "Just because Word 16.103.2 can achieve borderless printing does not mean that you can with Pages."
I understand that. But I think it's an actual bug somewhere between Pages and the Canon Printer driver. I do not have this problem with printing from other Apple apps, only with Pages.
You wrote: "I would not consider Pages an escape from Word owing to the huge feature gap between the two applications and lack of true document interoperability."
I understand. I am have been using Word professionally since Version 1.0 and consider myself an expert in all facets of its use. That's why I'd like to switch to Pages. I am retired now and the the level of functionality that Word provides is now more of a productivity hindrance these days than a positive due to MS's idiosyncratic interface choices. I'm not looking to switch to something similar, I'm looking to something less.