Yup - a little acetic acid goes a long way! Also, the reagent we use now is less caustic (pH of 11 or so) which is not as nasty. But we have a long way to go yet.
Since the focus is on making a very good, sharp and detailed negative in the field, we will put the emphasis on that first. If we can get a decent positive, all that much better.
That would be more likely if we could zero in on a more exact production procedure for the receiver material. Can you help us find it?
The plan published anticipates a $6 per sheet cost, so it is not for the very frugal or those who have other ways to process 4x5 negatives. That's one reason why the estimated production would be small, and we have been very cautious about committing the substantial funds this would need - if it is a real opportunity.