Technique can make a big difference in how much debris gets blown back on you.
If you're not already doing this, keep the discharge chute pointed downwind as much as possible. Take note of the wind before you start mowing a section and mow into the wind and downwind, not crosswind.
This will...
If you're going to mow it every two weeks, it'll only be 5' tall once.
Hire somebody to bale it. If it's good enough to feed to animals, you can sell the bales. If not, pay somebody to haul it off. You've got to get rid of the cuttings.
Then a regular mower can handle it.
Welcome to the forum, but embedded links on your first post may not be a good idea. I'm not going to click on it; maybe others will but I'd recommend they not.
If there's another way of posting the info contained in that link, I'd do it.
4 cycle.
Your tune up probably should include a new air filter, spark plug, oil change and removal of the fan housing to clean the cylinder cooling fins and investigate that oil leak. It looks like if this has ever been done, it was a long time ago.
It's probably a wise decision to buy a pair of mowers these days, given the situation with parts unavailability caused by planned as well as unplanned obsolescence.