I agree with @Mobjack Bay -- I suspect using both citric acid and vinegar can indeed cause bar soap to be softer. I don't know what people are doing when they use both, but if the "usual" dosage is used for each acid and they're combined together in one soap, that salt load may be too much of a good thing.
It may be (just a guess -- I don't have proof of this) that the total combined salt load should be kept below a certain amount to get the most benefits and the fewest disadvantages.
I wonder if too much salt is causing the long cook times?
Prior to getting the Sodium Gluconate, I was using CA/Vinegar. I never used the full amount of vinegar, never more than 150g in a batch of 900g of oils. However, I was still having trouble with long cook times.
When I used SG/water only, the batch cooked in 14 minutes.
Tonight, my trial batch with making adjustments for the CA and vinegar, is back to the long cook times.
However, while stirring/cooking/stirring/cooking I realized that maybe, to your point, the salt is the problem. I have a water softener and even though I don't use tap water straight from the faucet, I am using filtered water that came from the tap.
Is it possible that there is still salt getting through the filter and that combined with ca/vinegar and now SG that the cause is too much salt? Maybe I should just stop trying to use vinegar and try it with distilled water, ca/sg.