Hypercube Evolution Z axis adjustable flag for optical endstop

This thing is to flexible adjust an optical Z endstop on a Hypercube evolution. Main reason for the design was:

On my Hypercube Evolution with dual Z (https://www.thingiverse.com/make:532085) I experienced both stepper do not run exactly synchron which caused issues with the first layer after a print was done. Therefore after every print I needed to check the bed leveling on each side which was time consumption. With an endstop on each side the printer now levels itself with homing the Z axis