Macerating/dumping into septic system vent stack.

sch911 wrote:
Ignoring the legal aspects it should work, but be sure not to plug the vent up. I would run a snake through the vent first to make sure I could clean it out if necessary...

The first time you clog/fill faster than it will take you will be pumping waste on the ground before you even suspect a problem.
Consider the cost of a proper clean out versus the uncleanable mess if you pump out on the ground and where the mess will be (and stay till it's WASHED away) .