I ran out of blue filament but managed to swap in some white I had. The white was originally a roll of really bad filament that just wouldn't print on my old extruder It seems to be ok on the e3d hotend though.
I made the notches in the forks larger along with the spring clip that fit into them. Now when removing the uke from the forks it doesn't pull out if the strap gets caught etc
If you squint really hard and use some imagination you can see the notch on the spring.
I ordered, despite promising myself I'd wait, some black pla to make the small version, to make sure it works being printed at smaller sizes.