Hello Pfeil,
I actually tried two left-handed mice from Logitech.
One has hardware reversed buttons (Left-handed Lift model), and the other (M650 Left) relies on changing the options in Windows 10.
Curiously, for these two models, Logitech did not see fit to create a driver that allows you to customize the functions of the basic left/right buttons.
So I'm going to use the Lift Model, which doesn't require any system-level changes to the clicks, and that's fine.
Thanks for your help.
Have a nice weekend.
Edgar