And presumably glycerol doesn't affect the buffering ability of borax like glycol?
At 1:50 my scratchings on an envelope indicate there's 5g Borax - 0.4g Phenidone - 0.4g AA per litre (working). My maths has been known to err in the past but is there a decimal place wrong in there?
Long ago I made up some PC-glycerol and it appears to keep just fine. I had no glycol.