Splitting large multipolygons in Vespucci

I’ve been using Vespucci quite a bit in the last couple of months, it’s a little JOSM that lives in my pocket.

One operation I use often when working with MPs in JOSM is to draw “split ways” across them, then with the MP and way selected split it. This creates two MPs sharing the way as a border.

How can the same be achieved in Vespucci?

I can create a new relation, add all relevant ways to it, then remove the same members from the old one. This does however scale linearly with the number of ways, turning an operation that should take seconds into minutes for larger MPs. It’s also a bit error phrone as one could miss a way.

Are there better ways of splitting multipolygons in Vespucci?