Looks very much like an evolution of the setup on my 855 / 7 hoe.
To answer the question about the time to switch.
Takes me about 5 minutes to take the mmmower off.
Takes about 3 minutes to put the loader on.
Takes less than 5 minutes to mount the backhoe - takes longer to line it up than mount it. I only install the 3pt arms in the spring and fall. Rarely use them in the summer. Add a minute to take them off if required.
All the brackets stay in place.
Not racing, I'm sure I could change over in 15 minutes. If I really wanted to push it, could probably do it in 5 minutes complete.
Regardless, I still always look at the tractor to see what's on it, and if the deck is on, I think twice about whether I really want to dig today. Or, if hoe is on, I mow with the garden tractor this week. Call me lazy! I tend to group my tasks by equipment!