"Stepwisdom" and "step nomadism" are two competing philosophies of how to sequence code upgrades, and they have a very long history in Urbit.
Stepwisdom is the idea that the system should guarantee that every
update to a piece of code is run stepwise, in order. That is, you only
ever upgrade from version n to n+1. This is very nice for
developers -- instead of considering n different possible upgrade
scenarios, you can consider only one. This sounds so nice that we've
always planned to do it, though somehow we've never quite got there.