I would love to hear the reasoning behind this.
I vape ecigs, so I personally am not adverse to the presence of PG, I have vaped it all day long for the last 10 years. Keep it below 420F to avoid creating thermal degradation carcinogens. I have studied PG and VG thermal degradation and know the safe ranges, but MCT I dont know about so I wouldnt try it.
All of the distillates I have tried were thick like cold honey, this required a special atty. The motivating factor to try PG is to get a viscosity that will work in regular attys.