You are incorrect, or mis-understod. I am enabling the developer installer page on the player using the remote keys.
I finally got it to show up by moving to one of the other channels (not settings) at the top level and then doing the debug display and then the developer enable key combo. I'm not sure how important all of that was, but I tried it from various other places in the UI without it working.
I'm looking forward to playing with this! Thanks to Roku for releasing this!
Note that the key sequence is time limited (i.e. keys must be entered close enough together to be interpreted as a sequence). This doesn't mean that faster is better. A very consistently paced set of button presses where you see the lights on the front blink for each press generally works every time. It shouldn't matter where you are in the app because the first few keys are "Home" anyway. A nice consistent cadence is the most important part.