I found the same, which is why I taught myself how to produce Custom Remotes and then wrote that article. Interesting about the Android app, I might try it. A lot depends on what format it exports the codes in.
Sling did actually experiment with a learning system and the Solo & ProHD were fitted with IR Receivers for just that purpose. But they never really worked properly and eventually the whole idea was kicked into touch,
Yours is a pretty standard Xoro device and you should find the Custom Remote at Xoro HRK 7564 should work for you.
I am very disappointed with the slingbox. I havr several receivers, none are compatible with the remotes. The reason I bought the device was to watch television overseas, but when you can't change the channel, the box is useless.
That said, I have a Xoro HRS8560.
I was reading this website to add a custom remote.
Unfortunately I don't have the said receiver. However, I can control the receiver with my LG G4 cell phone.
I was looking at the free app 'IR Plus' for Android. With this application, one can export the remote's IR codes. There I get lost, but I ponder the possibility of this app being useful for this purpose?
My LG G4 cell phone can control every TV,.receiver, amplifier, etc. I have. I haven't found a device it can't control. If it doesn'twork, you can set up the phone to learn a device. This is what I expected from Slingbox. A learnable device. They are the experts in this field. Not LG.
Anyways, Slingbox's faulty and misleading advertising "watch tv from anywhere" simply isn't true. If they don't have a learnable receiver on their bix itself to transmit commands to a 3rd party device then you will never be in control and never be able to "watch tv anywhere" as one relies on Slingbox's impotent database of remote controls and Slingbox to update it (per customer requests). I have read people waiting for remote control support for more than four years!!