Yeah.
Now you're talking some sense.
BWV 903 is indeed a challenging piece, full of many subtleties, but it's not the kind of piece that you can't read through. The Hans Bischoff edition published by Alfred is OK: that's the one I have, mainly because it was cheap and I'm familiar with Bischoff's "style" as an editor, so I knew what to watch for should I go on to master the piece (or make an honest attempt!).
Maybe not sight-read at full tempo, of course, nor even complete accuracy, especially the fugue, but also the fantasia is kind of difficult to make sense of, all of the semi-strange filagreed runs shared between both hands (I know I can't! Haven't put in the hours with it!), but I'd have to think anyone who loves music and the keyboard instruments would get quite a bit out of familiarity with some of Bach's "tricks" in this one.
If I were in your place, would I spend a million hours trying to master it? Probably not, but only you can say for sure. Maybe you're a Wunderkind and it's easy for you. I wouldn't know. It will certainly lead you to discover other similarly "odd" chromatic moments in late baroque music, and elsewhere, which would be a good topic for conversation as well.
And, if you disapprove of some of the "tricks" of this kind of rambling toccata/fantasy style, then you'll know for the future what you dislike or like when it comes to selecting repertoire.
You should read it at the keyboard at least once, though: what have you got to lose?
Read everything at the keyboard. You don't "lose" anything except a few minutes here and there, and you refine your tastes and your reading ability. In this age of tablets and IMSLP, you don't even waste printer toner or paper, necessarily.