At the risk of being severely corrected by someone who knows better, I think it depends really. If you're heavy and ride hard (if you know what I mean?) then there's a danger of burping – although I think it's more likely at lower pressures. However, if you're a reasonable weight, etc, then you could be absolutely fine. I had no problem with normal BG and Nevegal combo on Stans rims, running them very low pressures, but then I am very light, I did ride several long black runs in Spain with them though, so they were quite tested! I've also got a mate who's a fair bit heavier than me running the 2.35 (non USTs) on Flows rims and hasn't had any burping problems. I rekcon it's probably worth a try… I hope that helps at least a little?