Even "work in progress pictures" would be an interesting insight into the design progress.

Btw: what are considering? A LED wih some specific protocol piloted over GPIO ? Or a LED using I2C ?

Also, "double tap to wake" (as featured on the original Jolla 1 and several other tablet and smartphones) was mentioned a few posts back. Is it something that would be possible (given your selected chipset and board) ?
I find it useful to quickly wake the phone to check status (charging, etc.)