This is the Alpa FPS kit as I used it. Different watch, but same setup when I photographed the Krayon Anywhere above. The setup is a bit cumbersome, and the FPS shutter speed (1/125s for flash sync) is not communicated to the back’s exif, a problem which is known to and acknowledged by the Alpa folks.
That's clear – but in this context here, we are talking about using this lens in a MFD macro setup. There's no alternative to mounting it on a novoflex bellows attached to an Alpa FPS which will give you flash sync of 1/125. There is no global shutter MFD back available to consumers and that's the whole point here.
Copal doesn't fit the lens and neither does the x-shutter.
The most practical solution is the FPS route – in fact, you can just order the Alpa Macro kit which includes both.
All the details and images of the ALPA product 020.020.010 ALPA Focus Stacking Kit FPS/105 float; article no 020.020.010; Jul 01, 2022www.alpa.swiss