Proper support for the VRC-1100 dongle was added in the December release and this was mentioned in the release announcement: https://osmc.tv/2019/01/osmcs-december-update-is-here-2/
Effectively, this means that the device is now correctly recognised as a remote rather than a keyboard.
As a result, all the buttons now work out of the box.
There is a long thread here in case you’re interested:
https://discourse.osmc.tv/t/using-the-ortek-vrc-1100-ir-dongle-with-osmc
However it does mean that if you had custom <keyboard> mappings then you’ll need to perform a one-off exercise to convert these to <remote> mappings.
https://kodi.wiki/view/Keymap#Remotes
I think there’s an addon that can help in this regard, though personally I don’t use this, as I prefer to edit the keymap file manually.