Here is the answer in writing that worked for me last night for the LE and the PLE, the vid suggests it’s the same for MIDI inserts
(Win 7 64-bit computer running Cubase 7.5.20) :
When I started, in the folder User/AppData/Roaming/Steinberg/Cubase 7.5_64/Presets, there was no “Logical Editor” subfolder there.
There was a folder called “Project Logical Editor”, but it had only one folder of presets, called: “Visibility”.
But in the In Program Files/Steinberg/Cubase 7.5/Presets folder, there were multiple folders of presets, for both editors.
So I copied the whole Logical Editor folder from there to User/AppData/Roaming/Steinberg/Cubase 7.5_64/Presets, and now a whole bunch of presets for the Logical Editor (where previously none did).
I also copied all the subfolders from Program Files/Steinberg/Cubase 7.5/Presets/Project Logical Editor to User/AppData/Roaming/Steinberg/Cubase 7.5_64/Presets/Project Logical Editor, told it I didn’t want to replace the only presets that were initially there (Visibility), and now I get a bunch of PLE presets opening up in Cubase too.
Now when I open Cubase 7.5.20, the PLE and LE presets are available.
For Mac: I think the answer is found in this post: Why are my Logical Editor Presets Missing? - #10 by catchawave - Cubase - Steinberg Forums
Hope that helps someone!