I've heard this about 'standard' Liquid Chalks having pof in before and whislt I couldn't confirm whether it's entirely accurate or not is seems likely that if they do, in most cases, it's a truly miiniscule amount. As well as supplying their own branded products, Rock Technologies actually make/re-brand Liquid Chalk for a number of other companies, Beal being the most obvious example (remember that next time your shelling out an extra £3 for the Beal version) and RT are a UK based company whom I believe have some level of specific climbing expertise at the helm. That being the case, it would seem unlikely they would use pof in their products. That's not to say they don't.
Having used Liquid Grip, it feels very different to standard Liquid Chalk. It has an almost tacky feel once dry, which is presumably a result of the pof and the reason I think it probably has a fair bit more rosin in it than standard liquid chalks - which generally feel dry to the touch once dry. As with Dave Mac I found its results variable: quite good/useful on very rough rock types, far less so on smoother grained rock and indoor walls. Having said that Leah Crane apparently thinks it's great, so what do I know.