Right, I'm pretty firmly in the "just actually write rules for everything" camp, and I'd argue this is a pretty heavy yoke on that kind of design. You're talking on extra design work for a return that at best exists entirely in your own head, and at worst, actively makes a player have a worse time. If the outcome is a rule that is actively bad for players to engage with, the best outcome is that they don't, and the worst case is that they don't put that together and do (probably once).
The rule is either only valuable as set dressing for the GM's mental state, presents an avoidable knowledge/engagement tax on the players, or outright encourages obscurantism if the GM wants players to interact with the rule.
To take it back to the actual example, rope swinging has to present a reasonable incomparable advantage over normal movement relative to the risk of presents to be worth considering. Maybe if it's situational enough to be a forced action you'd need to resolve, and something a player could optionally build to be better at, you'd have something. Otherwise.... Why are you allowing the action at all?