Hm, that's a tough one; I have no experience with copper/chloride bleach in a reversal application. In fact, I'm rather surprised it works at all as I'd expect it to be a rehalogenating bleach, whereas you need a non-rehalogenating bleach for reversal. I had to google a bit top come up with this thread which was possibly your inspiration:
https://www.photrio.com/forum/threads/copper-sulphate-b-w-reversal-bleach.137943/
To speed things up, intuitively I would suggest trying e.g. ammonium chloride instead of sodium chloride (together with copper sulfate of course), as sodium tends to slow such processes down. However, introducing ammonium may enhance the blixing effect of the bleach (as mentioned by PE in the thread linked to above). Maybe the issue is insignificant, maybe it isn't. Hard to tell.
Another option would be to figure out at which pH the bleach works fastest. We know that with color bleaches, the bleaching speed is very dependent on correct pH and I can imagine the same is just as true for copper sulfate bleaches - but I don't know for sure. I do notice that the copper/chloride bleaches generally also list an acid in the formula, so presumably bleach speed is highest at somewhat low pH. Do you add any acid to your bleach?
Finally, a very obvious route is just to increase the copper sulfate concentration (and perhaps the chloride concentration as well). It will speed things up, but I'm not sure if it will result in the kind of speed increase you're looking for. Still, I guesstimate it may be feasible to cut bleach time in half this way.
