You can of course have more than one event on a single day – the limitation only exists in terms of recurring event support.
So, if you want to set up an event and have it recur daily Monday-Saturday (but with two performances, Wednesday and Saturday) then I’m afraid you can’t do that with the current recurring event system. You could of course add matinĂ©e performances with standalone events and simply link to them from other events.
If this is common in the theatrical and perhaps other sectors it could certainly be worth checking out our UserVoice page. You can then show your support for anyone else who has already proposed this, or even create your own request.