I thought belaeys were awful! The chamfered edges made them awful, if the whole pad touched the rim they may actually be decent!
Id agree the rim makes a big difference, my atomz rim was shite for a grind where as my echo rims have always been alot better, I thinks it's worth the weigh difference IMO.
Also I think smooth rims are really good with the right setup aslong as you dont ride in rain, ideally old zoos but there are other pads that work well on smooth LGMs for example