I just had a thought of what is perhaps one of the unintended consequences of mixed member proportional. It's theoretical, perhaps.
Right now, as much as many may disagree, central party headquarters run the local riding associations for the most part. If the party wants to run a star candidate, or a floor crossing candidate, or designate a certain number of candidates from a particular representative group, they have to scope out a riding and essentially parachute the candidate there or supplant the existing nomination process.
Generally, this practice is accepted if you're a party member outside the riding; not so good if you're working to be nominated or working for a nominee within the riding.
With mixed member proportional, that's not entirely necessary. A riding is free to select their candidate, while stars and special candidates can be reserved for the list.
It won't eliminate it of course, as the central headquarters should retain some veto capability, but it won't be necessary to remove a valued member in place for a parachuted candidate.