Okay so basic test was, Flexicolor C-41, diluted in to 1+9, and about ~1.2mg/litre of potassium iodide added. A while back Daire Quinlan tried a C-41 1+9 stand development, I decided to expand the idea in the search for various ways for good quality processing of C-41 at 20 degrees celsius (harder than it sounds).
Processed at ~20 degrees celsius, for an hour, pure stand iirc.
I was going to adjust pH to put it around 10.2 or so, but then I thought stand development may have a compensating effect, which means the RGB densities shouldn't be too far off each other, and potassium iodide also is supposed to promote even layer development between layers.
I've included the original RGB histograms on top of the image so you can see the rough density for each channel, remember highlights to right on a histogram on negative films means denser, and to the left is thin.
The results are dense with a thin range, (dMax close to dMin for each channel), however, it's actually better than normal C-41 processing at 20 degrees celsius in this regard. Also some of the density may be attributed to the uneven developed areas which were denser as you can see (blown out or very bright as I corrected to the main part of the image).
But, with agitation it should prevent uneven development, but that density shall still... so the solution is shorter time... or more potassium iodide, I think I will try more potassium iodide.
Another word on the density... it was very old no-name (unknown) brand 400 ISO film I got for 50 cents a roll at a fair, also overexposed, so there is base fog to it, so I feel dMin would be lower (good) with fresh film
Also grain is actually normal ocompared to regular proces C-41 with this film, where as Daire Quinlan experienced increased (excessive?) grain, may be a result of the potassium iodide I added, but it should be confirmed with fresh and good fine grained film.
Test #2 will increase the potassium iodide and increased agitation (probably at 20 minute and 40 minute marks), I am not sure how much to increase it by, perhaps 4x.
The goals are to get even development, a little less density, and much lower dMin.