Yeah, devs wont help when it comes to installtointernal.
You have to understand why.
installtointernal needs support to recognize the internal RAM - it´s impossible to do this on every box on the market
There is no big advantage running LE/CE from internal RAM,
if You are using a good/fast SD card .
I checked it up on my Odroid N2
Running on EMMC and running from fast SD card I can´t see ab big difference.
All my S905X/S912 boxes are running perfect using SD card and I never had issues after updates.
That´s another story, many people bricked the box trying updates running on internal memory