Instead of mimicking the original shift knob, why not customize a replacement. This design is printable upright due to a cone base limiting overhang. Otherwise it's a 2" sphere. The bottom hole is hexagonal for inserting a 3/8-24 coupler nut. Hopefully that works with low infill. The common nut I found is 1-1/8" long for a 9/16" wrench. This 4-speed layout is unique to convey more information about the gears. Some may not find it intuitive. What do you think?

I haven't printed it yet (Dec 2025). I wanted to post the design online first. Then shop it around forums to get feedback from others. So this printable may get updated later.