Yeah, I was mostly hoping for RAW clarifications and IRL experience. That example of wrestling with athletic tape was very useful. I figured you'd need full use of your fingers/palm to get enough leverage to actually hold on, or at least, not have it impeded.
Although... if it lets you carry items, and therefore weapons... can you use the weapon while having the caestus on? And does THAT get impeded? Because if it does, that would seem to imply that it should affect other similar things.