Door Handle/ Stair Rail question/observation?

I had no problem installing the port hole on my door.  I had no extra room on the flange, but it all worked out just fine and I've had no leaks or other problems other than very slightly compressing the Styrofoam when I tightened down the through bolts that hold the port hole and ring on place.  

Who ever wrote that declaration may not have actually installed one or got one with a flange that was 1 1/4".  When I return from Colombia, I will look up the one I purchased on Amazon and will post the link for that particular porthole.  Motor7, since you are relatively new to the board, you may not have noticed that sometimes people post statements in the absolute when they don't really know all the facts and variables.