I've got AH working pretty well in XP11 now, with a caveat that you have to import custom aircraft in XP10.
My method. This assumes that you have both a good install of XP10 and XP11 and that you are familiar with:
Install AH in a folder outside of the default C:\Program Files (x86) and set it up for XP10 per the MUDSPIKE article. I use C:\Simulations as a base folder for most of my sims, so during the AH install, I point to this folder as the AH install location. AH will create an AirHauler for X-Plane folder in this location. Moving it out of the default folder avoids any UAC issues that might cause some features not to work. So my XP10 install of AH lands in C:\Simulations\AirHauler for X-Plane.
Create a company and import all of the aircraft that you plan to buy/lease during a career. Note that you don't have to buy or these aircraft of take a job, just import then so that they will be available to you later.
Copy the whole AH install folder to another location. I used C:\Simulations\Just Flight\AirHauler for X-Plane, Launch this version of AH and in Options point the x-plane.exe path to your XP11 install folder. Shut down AH.
Copy from \X-Plane 10\Resources\plugins 3 files: XPUIPCOffsets.cfg, XPUIPC.xpl, and AHPlugin.xpl. Put these in the same folder in XP11.
Install XPUIPC for X-Plane in your X-Plane 11 folder just like you did in step 1.
Go fly like the big freight dog that you are.
In fact it looks like the stock market functionality is working as well, so I bought 10 shares of Boeing Aircraft.
I used medium difficulty because I wanted to test the Carenado PC-12 in XP11 and it worked perfectly as far as I could tell.
First job completed. Used time acceleration for this test, because I need to get some sleep!
Stock market feature. Did not test fuel prices. Boeing up 1.25% today - yeah.
"It's hard work being this good."
You've got cargo to unload Mr. Cut the fuel load a little close, oops.