Does yours have the sleeve, post a pic? Does it work? What year is yours? I hadn't seen these before and am surprised no one has posted it before. Looks secure enough for me.
In my 1 st skoolie I used a heavy duty slide (Barrel) bolt on the inside of the rear E-exit..I didn't want to be fumbling with a lock if we needed to get out in a hurry. Those slide bolts have a hole in them for a pad lock to keep someone from unlocking it via a broken window so you could ad a pad lock while you were out. On the front doors, I used a simple hasp with 2 "staples" One staple to lock the doors while we were out and the other staple to lock the hasp safely out of the way so no one could lock us inside.
Anyway, my main point is to keep the Emergency exit easily usable at least while you and your family are in your bus.
This is my super fancy security system for the back door:
We basically had a few hours to whip something together before going to San Francisco, and it works just fine. The bus door locks with the handle inside, and the driver's door with the key.