In the absence of a driver you could just call the API directly in your buttons/macros. I've done that with a few different devices that didn't have a driver. To make it easier you can create macros and then just pass in the parameters that are different and have the macro build the http request.
I may use the model I use with ATV and have both IP and IR control and the config is triggered by a variable (use IR or IP).
On a side note, the Dune Duo 8k Cinema device is interesting in that it has a certified (Netflix, Google, etc) board built in along with their proprietary 8K board. This would allow me to get rid of the Roku and possibly the ATV.