I don’t think FT is keen, and I’m not sure they are suitable for the market FT is targeting - while useful if you know what you’re doing they are too dangerous and not useful enough to retail investors to justify that. They’d also probably be quite complex to handle in the app (so lots of work), and cause more support load too.
See the recent Robinhood suicide for an example of the extreme situations they can put retail investors in. There are so many other areas Freetrade could look at first (limit orders, SIPPs, JISAs, other markets).