So what's in canon and what's out of canon? To put it mildly, canon is what the players make of it. Within the CharLoft, due to the unlimited number of timelines on offer, technically, in-canon is the events that actually occur within that world, and whatever is brought to it; out-of-canon would be the events that take place on other worlds. Canon for a particular world - i.e., whether events that occur within CharLoft have a permanent effect on that character within their own world - is up to the player (and gamemaster of that world, as the case may be).

Or in short, 'no, you can't go to the CharLoft and bring a chainsaw back to your medieval fantasy world without the permission of whoever runs that world, but if you try to cut someone up in the CharLoft, they're going to remember it.' Simple, no?