[PnP] Ending Insubstantiability early

[Alex Koponen]

The only spells that can be cast while insubstantial are Travel Powers.
Is it possible to end the spell early?
Perhaps I've missed it or forgotten it, but I don't remember any way to
end a spell early other than to Dispel it. Since Dispel cannot be cast
while insubstantial is the insubstantial person stuck staying
insubstantial until someone who isn't insubstantial casts Dispel/Banish
or until the duration of the spell ends?