An update on my attempts (without paying an arm and a leg for the ebooks):
The bars that I added the sodium lactate to at 3% have a springy feel, long after bars that I didn't add to have cured hard. Blech. However, adding 1 tblsp of unflavored yogurt (I used greek) did not lead to springy bars but did help with the fluidity. I did the water at 38% in the soapcalc calculations on both batches, and added an extra tablespoon once it got close to the end. I did not add anything extra to the recipe other than the sodium lactate/yogurt. My recipe is a high lard.
One major problem I have is stickblending like that led to splattering because I had to keep pulling the blender up out of the batter, and I'd get hot air pockets and ploop hot molten soap everywhere! This alone is keeping me shying away from continuing in these experiements.
My conclusion? Adding yogurt does help with fluidity, adding sodium lactate in that quantity makes an odd bar. Splattering hot soap is bad. Some of the method is adoptable for HP/ rebatch (of still fluid batches), as in starting with higher temperatures of oil and lye and stick blending off and on for a while speeds things up. All the extra "stuff" leads to a bleh bar (for me). I love my microwave (put the whole crock insert with the oils in there to preheat, 45 seconds at a time).....
Curious if anyone really has done the weigh the bar thing...or maybe a lather test...