The USB2BT PLUS is exactly what I've been looking for, I have tired a few other devices that offer USB hid devices to be sent over bt, and none of them work for multiple hid devices. for example I have a keyboard that has a built in usb hub and shows up at 4 devices 1 for the k/b it self and 3 for the additional ports. This device seems to have no problem with these kind of products, it even lets me plug a wired/wireless mouse into the keyboard's USB hub, re-pair and works no problem, ive not been able to find the limit of amount of devices that you can plug in the the USB2BT yet, so far ive had 5 thing plugged in to a hub at once and all would work. The documentation is in Japanese but with todays tech that's a non issue, the software is in English and has a great debug feature if you wanna see what the unit is doing in its terminal. its only classic Bluetooth so no luck pairing to LE devices. Unit looks great in the acrylic case, and shipped fast all the way from Japan. 10/10 would buy again.
I was looking for a cable checker, but none is as complete as this solution. Build quality is awesome. Packaging was very good, everything works as expected. One thing missing is some status screen when no cable is inserted, maybe some icons or a text.
I had to pay 26 USD in customs which is quite high, so be aware of this if you are from Skandinavia or EU, so it was actually cheaper to buy from ebay or amazon.
June 22, 2019
Pretty good product, but doesn't support Bluetooth LE.
I really, really like this thing. It works with almost everything I tried it on: Linux, Windows, iPhone, Macbook. It's great.
Turns out it's using Bluetooth Classic (this is mentioned on either the website or the docs, but I missed it), so I couldn't use it with a Bluetooth LE-only receiver, which I needed for other purposes.
The docs, at the time I bought this, were only available in Japanese, but thankfully it's fairly easy to figure out how to use just by playing with it. You can also try Google Translate on the website, which worked pretty well.