The Drake is a 12" bowl.
It can be set as close to the wall as 10-7/8"
The Unifit that some toilets use, like the Vespin or Carlyle will not work with standard bowls like that of the Drake.
If you want to pull the bowl back closer to the wall, you will need to buy something that uses a 14" Unifit.
Toilets that can use the 14" Unifit to move the bowl would be
Below is a toilet that does use the Unifit adapter.
The one pictured is the Toto Carlyle.
If someone is leaning back on the tank like an easy chair, really?
They lean back on the tank?
Don't all toilets use a tank and bowl.
I don't get the question.
And tanks don't normally touch a wall either.