Yes, I'm suggesting that if the OP thinks a monobath might solve the tray space problem in his Afghan Box Camera build, he start testing by adding some hypo crystals to his print developer. This will a) let him test whether fixing is too fast for development rate (probably correctable by changing dilution level of the developer) and b) let him test whether the result gives a desirable appearance in a final print, stains the print, etc. And it's cheap to try -- hypo crystals can even be sourced locally, in most communities, as chlorine reducer from pool & spa suppliers (and $20 worth will last years in this kind of usage unless you're out with the camera every day).
As Matt pointed out above, my HC-110 monobath from 2003 was the basis for not only Famous Format/New55's first monobath release, but also led them to the "goop" for the New 55 actual pos/neg instant photography material. I doubt Df96 is directly based on my formula (MSDS doesn't show ingredients I'd expect if HC-110 were involved, and buying Kodak product to make a Cinestill product wouldn't be cost effective), but I suspect the renewed interest in monobath in general came from my experiments.