As far as I'm aware, they haven't, but I don't want to be naive. It may be that they stipulate their members to put in particular subjects for debate, but I really doubt it. I think members spot that and don't like it on either side. This is their place. It is their home, more than the chamber in many ways, which is inevitably dominated by whips of both sides, by the government and by the opposition, who have 20 days a year, and by the parties. Backbenchers would resent it if the whips did do that.
It may occasionally be attempted. I detect that a smaller party may have tried to get a slot in Westminster Hall for what is really a pretty partisan debate, because they have less chance, so they raise a subject that is of interest mainly to them.
I think that is seen as fair enough, but by and large, this is backbench territory and it's respected as such.