User blog comment:YourPrivateNightmare/Why I think the Gangplank rework failed/@comment-24795478-20150725173402/@comment-24795478-20150725202135

With regular build it kinda hard, but with 20 stack occult and 3 BF item it's much easier ( 3 upgrade at ~33 mins)

Still not pratical in real game though, maybe riot intention was only allow him 1 upgrade only in a regular map.