So it took me a few months between first committing to the idea, getting the parts and making the changes, then 4 track visits and a ton of attempts to optimize the SuperRok setup - but I can finally report that for my purposes, on one of the tighter tracks that exist the stock rev limited RokGP coil turns a faster time than the SuperRok coil does even when screaming it all the way to 17k. In the end I proved it by swapping the coil mid-session this time, and immediately the times drop by half a second.
I’m still surprised by this result, but there it is, though I have zero doubt that on a more wide open track (which is actually more typical of the ‘average’ track) the results would be exactly reversed (e.g., such tracks are what the SuperRok were designed for), and plan to keep the SuperRok coil in my toolbox for just those occasions. 
Ultimately, it was a lot of time and energy to spend to end up going slower, but I did learn some things along the way and one positive that came out of it is that I could actually tune my kart the way I’m used to (spark plug insulator or exhaust header color), which is something that’s impossible if an engine is on the rev limiter for 7 seconds at a time. (in those cases, the insulator is going to always look black even if you’re actually lean, which makes it awfully hard to know where you’re at jetting-wise, something I still will need to figure out how to deal with since I am now back to being rev limited to 15k)