Robert, I am here to inject a sombre and serious comment, as requested
The idea of the 'roadmap' for a lap steel is brilliant - and actually, when I first got my lap steel some 18 years ago now, it already had a series of stickers on it to guide the player toward playing the right notes at the right time!
As a guitar player predominantly, I tend to think of chords and inversions as I would play them on 6-string, then try to transpose that to steel, so the 'map' is very easy to implement, but with pedals and knee levers it all starts to get a bit tricky. Although I suppose with some careful consideration I could probably get my brain to swap bar slants with pedal and knee movement... and possibly bowel movement. Oh no, there we go - the inevitable return to toilet humour! 5 lines of 'serious' talk before I did though, which I think may be a personal best
I recall someone mentioning an Excel spreadsheet that shows you all the notes on a pedal steel and how they change with the copedent, which I guess could be useful if one had a computer next to the steel. I may make myself a board/map for the back neck on my D10, come to think of it, as I struggle enough playing that without pedals. Which is odd, as I never used to get so flustered with a 6-string C6 lap steel, and those strings are still present on my current guitar!
But to land the plane on this thought, a board with note names is (to me, at least) a lot more useful than any computerised thingy as most of my playing is done without plugging anything in at the moment. Being able to sit down for 5 minutes and still learn something is quite an appealing prospect just now.
Do you know if any cereal manufacturers do a Sho-Bud sized box?