going from those screens and the pdf linked on the site the app is an instant disappointment for me! They still, arbitrarily, force certain power levels for the five modes
True, but...
I don't blame Giant for maintaining up to 15 power levels distributed into 5 presets. It is fine for me, which I will explain soon.
Specialized Turbo e-bikes let you set infinite support level in range from 0 to 100% in 5% increments (Mission Control app) or 1% increments (BLEvo app) but only distributed into 3 presets. If the rider wants to keep it easy, he/she needs to decide in advance (typically, prior to the ride) if they need weaker of stronger assistance on that day. Of course, manipulating the assistance levels can be done anytime en route as well. Still, only three assistance presets seem quite limiting to me.
The situation with Giant is not hopeless. 15 assistance levels in 5 presets (and you can manipulate them with Ride Control App) is not that restricting, and it is easier to choose from 5 presets than from 3 during the ride.
If I could make any advice to Giant Co., I would rather suggest them to emulate Specialized in another matter: Limiting the Max Motor Power (or, Max Motor Current). At the moment, if you select 100% Eco in a Giant, it roughly means the motor responds with 1 Watt for each one Watt you input in the cranks. If you can input 250 W yourself, the motor will respond with 250 W assistance even in the
Eco mode! (SyncDrive Pro can pump up to 520 W). It means a strong rider gets far too much of assistance, the assistance that might be unwanted because the rider might prefer a long range on the battery or a better workout. The motor max current (effectively: Motor Max Power) setting for each assistance preset would be very very valuable for Giant e-bikes.