compact reversed cim gearbox and output shaft question

[Aaron Ng]

high speed: 18.77 ft/s
low speed: 8.46 ft/s
weight: 3.4lbs without cims, 9lbs with cims.

tl;dr: How can I extend the output shaft of the ball shifter without having to knock out the roll pin or use a coupler?

I designed this to be something that I would personally be comfortable with making during build season, so everything is cots with the exception of the gearbox plates.

The problem comes with the output shaft of the ball shifter. Even when using the long version, and using chain in tube, the output shaft still isn't long enough.

Currently, my solution is to knock out the roll pin and replace the output shaft. but removing a roll pin would fall under "something I wouldn't do during build season", or really in general.

another solution is to use a coupler, but I would like to avoid that if I can.

Has anyone come up with a elegant way to direct drive using the output of the ball shifter?