I'd like to play in this if it happens.
Barnstorming was a phenomenon of the 20's and 30's, as most of the pilots involved were veteran pilots of World War I.
However, if 2% of the population of base line earth are jumpers, you are talking about several millions of people doing it.
That seems a lot, if baseline Earth is going to have a history anything at all like what we are used to considering.
Especially if actions taken while jumping have an effect on the the baseline world.