It's a bit more hassle when working on the bike, but they are popular where I live. I prefer having a strap around the ankles, perhaps with a crank that has a "small" chain guard (like many MTB low end Shimano cranks). Got some hi-vis elastic bands and sewn velcro onto them. Works like a charm.

This might help:

German store:
https://www.bike24.com/1.php?content...derby=2;page=2

Amazon:
https://www.amazon.com/gp/search/ref=as_li_qf_sp_sr_il_tl?ie=UTF8&tag=ciklogremlin-20&keywords=sks%20chainboard&index=aps&camp=1789&creative=9325&linkCode=xm2&linkId=685eba32059e2a83b f1dca408df0b9e8

Hi-vis velcro straps - factory made:
https://www.amazon.com/gp/search/ref...3f788eff40ec15