I’ve never seen that combination before, but here it is.
Stansted is a little more inconvenient than Gatwick or Heathrow, so far as getting to central London, but not much more.
Stansted would also be convenient if you were getting a budget carrier flight to somewhere else.
You could also decide to go to Cambridge or another English town rather than directly into London.
I took a quick look at the fares and they are cheaper than most or maybe all other options right now.
It would also be possible to combine a Zoom flight in/out of Stansted and a Zoom flight in/out of Gatwick, depending how the dates and prices work. Indeed, you could even combine this with a flight in/out of Glasgow.