Two new routes have been announced today – the E3X starting tomorrow (7 May) and the E1X next Tuesday (14 May).
The E1X will stop at Dundee, Kinross, Edinburgh and Wallyford P&R to charge, which explains this sighting from a couple of months ago.

The E3X will only stop at Dundee, Perth City Centre and Glasgow (four a times day Glasgow to/from Perth, with two extending out to Dundee).We'll be launching some additional services over the next couple of weeks. As well as providing express connections from Dundee to Edinburgh and Glasgow, these will connect new stops to the Ember network.
The E1X will stop at Dundee, Kinross, Edinburgh and Wallyford P&R to charge, which explains this sighting from a couple of months ago.
This is only two a day to start with, but I imagine it will be very popular since the 1hr30 journey time from Dundee to Edinburgh is faster than Citylink and Flixbus.Didn't get a registration, but curiously saw an Ember coach at Wallyford Park & Ride this afternoon around 1230.
It appeared to be testing a new electric charger in the bus stops beside the P&R (that I didn't know were there)
Bit out the way for them?