You could put zippers on all 3 openings.
You could put shock cord cinches on all 3 openings.
You could put Omni-Tape on all 3 openings.
You could do any combination of zippers, and/or shock cord, and/or Omni-Tape on all 3 openings.
In a nutshell, I prefer to have a way to get out the bottom quickly and easily as well as a way to easily slide the bug net off a fully loaded hammock to access things, setup/take down quilts, etc.
This mod fit the bill.