Thanks for your (most prompt) reply. I had not yet been actually working with a document...just reading through various "help topics where I encountered the following:
To loosen spacing in 10% increments, press ...
To tighten spacing in 10% decrements, press ...
To loosen spacing in 50% increments, press ...
To tighten spacing in 50% decrements, press ...
I have now looked at the "Character Panel" while editing a document, and clearly see the Tracking and kerning properties displayed as ‰, contrary to what is stated in the help function. Obviously, ‰ would make much more sense, and at least be consistent with Adobe InDesign. Presumably the actual Character Panel displays the correct measurement unit. But perhaps when Affinity support catches up with their backlog someone might respond to confirm the correct unit of measure...given the apparent conflict...and most likely investigate "fixing" the help screen.
Again, thanks!