When the parties agree, then yes, I think that should be the case.
A leave provision might be better than nothing, but in my respectful submission, I just don't think limiting prelims, because we already have the opportunity if you have a prelim to agree, for example, to concede committal.
One of your colleagues in the House, whose name escapes me at the moment, suggested that discoveries are a way around this. But discoveries in Ontario at least, the practice we have is that if there's going to be a discovery, we schedule a prelim but I concede committals, so we don't need a judge in the room. There's no jurisdiction in the Criminal Code right now to have a discovery without the prelim being the kind of procedural framework for it.
There are all sorts of things we can do to encourage discoveries. I don't think we should be tinkering with limiting prelims when there are other things we can do.