... with holes for mics, USB ...

Looks a bit like one of those jackets you see miniature dogs wearing. Also you won’t be able to use either the wireless adaptor or the the tripod adaptor.

Yeah :-) ... and you can wear it without case, but with protection:

Hello and good day BeterBan. Thank you for sharing this accessory with us today and thank you for your support.

With this case, OP reminds me a lot to Nintendo Wii controller.

Cool! Thanks for sharing!

That looks great for everyday use in safe countries... but here in Brazil, people get their phones and cameras stolen on a daily basis, in broad daylight too.

And a little silicone case with a strap that can easily be ripped off with the tiniest force won't help much there.

Have you seen anyone make sturdier cases for Osmo with a strap? That would be great if someone made it as sturdy as the one that comes with it, without locking/blocking the gimbal itself.

I don’t think so, many warnings regarding OP in some operations overheating, I don’t believe putting a rubber jacket on it will help. Try it on a hot day, go get a rubber suit and wear it for a couple of hours and see how hot you get ;+)