If I’m out all day and know the conditions are going to be bad, I use dry suit wrist cuffs (the ankle cuffs are quite large for dry suits) over the top of the shoe neoprene to create a very good seal. Grip Grab and VeloToze seem to be the main bike specific ones.
For general use and commuting I don’t bother – Light rain, my Altura MTB trousers are fine for keeping the majority of the rain out. Heavy rain, I use waterproof pants, which covers the cuff so keeps my feet dry.
That said the PX shoes are a bargain compared to the MW7 (I have two pairs of MW7’s).