While aging does improve flavor, many tobacco blends simply don't yield an intense, robust flavor after extraction. For my taste, of the 250+ tobacco blends I've extracted only around a dozen produced -great- flavor, that's why I continue to try so many different tobaccos.
Hot PG is an excellent extraction method (as is cold PG), and there are two very detailed threads which discuss it in detail. It was my primary method of extraction before converting to hot ethanol earlier this year. My main complaint with using PG as an extraction solvent is that it produces a low performance NET, it's gunky. You can't freeze filter PG based extracts so you must live with re-wicking/dry-burning after every 5ml or so.
Hot PG is an excellent extraction method (as is cold PG), and there are two very detailed threads which discuss it in detail. It was my primary method of extraction before converting to hot ethanol earlier this year. My main complaint with using PG as an extraction solvent is that it produces a low performance NET, it's gunky. You can't freeze filter PG based extracts so you must live with re-wicking/dry-burning after every 5ml or so.