
vanilla, contact your CURRIE vendor with your questions. sometimes there's a label on the equipment, stating maximum power recommended.
i have personally driven my CRYSTALYTE hub motor from 36v to 72v, with no adverse effects. the controller i used came with the hub, and was designed to be able to handle the 72volts. during operation, i would place my hand on the hub and the controller. there was only one incident when the hub became quite hot, and that was after a slow, steep climb.
i'm not advising you to do so, but you COULD increase to 30vdc. first, place your driven wheel off the ground(no-load), slowly apply power and monitor both hub and controller. monitor the situation for heat buildup, unusual noises and smells. if you pass this test, jump on your bike and pedal it on level ground. slowly apply power while pedal assisting,monitoring for the same unusual conditions. be sure you do not apply power from a standing still at this point. if all is going well, find a medium hill, get a running start, then apply power, using pedal assist. after 30 seconds of operation, get off the bike and touch the hub motor and controller. if either component is hot, pedal home without using hub motor. if the hub and controller is warm,do not apply power from a dead start to continue uphill.
if all goes well, it's up to you if you wish to continue testing with more voltage. you could attempt to do so at your risk. you could change to a higher-capacity controller which could handle 36v or 36-72v, and keep experimenting with more power. it's completely up to you. you are overstressing your equipment, so you should be willing to accept the consequences in the worst-case scenario.