From the earlier thread.

https://talk.newagtalk.com/forums/thread-view.asp?tid=931426

I emailed Pella and they had no ready made solution other than to suggest the aftermarket type pole but that they could not endorse any other company's product and would not warranty them. (Window warranty is long expired anyhow.)

I did come up with the aftermarket Pella 39-105 operator adapters to fit the oddball 11 spline Pella shaft. The Clerestory poles also shown in this link are non flexible and only work if you can stand directly under the window. The angles are wrong if you are trying to reach over and up like in this situation. Plus the prices for those poles are exorbitant.

https://www.amscousa.com/Window_Hardware/Operators/Clerestory_Extension_Poles_and_Adapters.htm

The adapter slides on the Pella splines and locks down with a setscrew. The drive end takes a 5/8 socket to turn it.

Also came up with a spring loaded universal joint to help support the socket a bit getting on to the drive adapter.

http://sastool.com/spring-universal-joint-mpp.html

Picked up a 30" long 3/8 drive extension bar off Amazon and used an existing speed handle and socket.

Here is a MP4 file of cranking the window open and shut.

https://photos.imageevent.com/vprb/pellawindowextensioncrankadapter/20200625_161029.mp4

It's 160Mb so it will take a bit to load on slower connections.