I'm a newbie, so carefully vette anything I say for logical inconsistencies and misinterpretations

I have the OF1010. While it's possible to go straight to the edge of the guide rail with the bit, I don't, because I don't want to take pieces off the rubber strip that'd confuse me when I'm trying to align the saw. Instead, I draw a line on a piece of scrap, align that with the guide rail, cut a bit, measure the difference, and use that in aligning my actual pieces. But with the fine adjuster and a block of scrap you can put the bit anywhere you want.
My memory of the fine adjuster sold for use with the 1400 is that it's a nicer execution than the one sold for the 1010 (and I should get one, 'cause I also think it'll work fine with the 1010).
In fact... you may have just convinced me that I need to get some thin sacrificial HDF, rip some hardwood to the size of the track on the rail that the router guide runs on, and just glue up a bunch of rails that I can progressively adjust the router to take a hair off of so that I can use them for alignment in the same way that the rubber strip guides the saw.
Which is probably exactly what you're already doing.