Thanks yawor - using the FireTV Home button worked :-)
I am looking forward to when long-press functionality will be possible with Flirc 2 - then I would assign a normal press for 'Kodi Home' and a long press for 'Android Home'.
Using Wake/Suspend from Media Keys also worked for putting the unit into standby, but curiously it would not allow resume from standby.
For the Mouse activation, it's not actually a mouse event as such (or perhaps it is, but I don't understand it sufficiently) - it's an I/R function that just makes the mouse pointer appear on screen. After which, you need t