Deluxe Leg Extensions - 4 Pack - Medium Size (only compatible with Deluxe Model)

Can you connect two extensions together to make the neat feeder even higher?

How far do the legs raise the bottom of the bowl - where the pet actually gets the food. I was very disappointed to see that these are even necessary.

Will the large one work with the express model?

I have a Deluxe system (base & 1 set of leg extensions already). I need it to be taller. Can a 2nd set of leg extensions be added for more height?