Are you familiar with the area he is speaking about? it is NO WHERE near the engine or any other moving parts. It is up pretty high and will not interfere with anything.
On my 99 sierra, i relocated the jack in the aux battery area.
The battery box is a good idea.
I know exactly where he's talking about. It's the storage on the front left end behind the left headlight. Why would you put things in a place where they are not designed for the purpose.
Tahoes have little spaces compared to its size. Especially, the glove compartment is so small it can barely fit the manual. I wish they had a space underneath the carpeting area in the back. My MDX had this. You can actually put lots of things in it and no one will notice there is even a space underneath.