That normally shouldn't be possible. Your maximum height is 600 feet. I've found that under extreme conditions, Genesis can bypass safety restraints and engage the full use of a operative's power. You growing to 1000 feet in order to save the Capitol is an example. If trained further, one could potentially activate it on command. The drawback is that after 30 minutes of use, the safeties automatically reengage, and reduce your strength and normal abilities by 75% for 3 days. I have yet to figure out what my, Murph's, and Minerva's "Limit" are though, so you remain the only one capable of it.