I can already do what you describe, send throttle inputs, down to 1% (or thereabouts), by using autohotkey (a very powerful little thing it is).
There's more complicated problems that it seems. Even with devicelink, IL-2 behaves just the same as if using the keyboards (only difference is more accuracy in the 'axis'). This means to move throttle 2 after moving throttle 1, we must select engine 2 - and upon doing that, it copies all the settings from engine 1, onto engine 2. The prop pitch lever on engine 2, for example, flies instantly into the position of prop pitch for engine 1. And then one must again send a command to make the prop pitch lever go back to where it was. But it moves slowly. It takes up to a second for it to get there. Meanwhile, if you select any other engine (like moving the throttle or prop pitch on engine 1) before it finished moving, it gets stuck halfway. Moving two levers at the same time on two different engines makes this problem very visible.
My 2.5 version (unreleased) has a built in timer that delays the movement on engine 1, until prop pitch lever on engine 2 has finished moving.
As long as one is only manipulating a single engine in peace, at a time, not much strangeness can be seen. But try moving two engine controls at the same time (and if the prop pitch levers in particular are not in the same position on both engines), it'll be laggy and look bad when the levers and throttles move a bit, switch to other engine, move a bit, switch to other, etc (and a noticable lag it is with up to 1 second if the prop pitch levers differ much on both engines).
By reading data from the game, I could find out if the in game lever is out of sync with the physical lever for each engine, and just force an update if such is the case. It should allow much more practical and accurate operation by, perhaps, letting the throttles always have priority and sorting out the problems of the prop pitch not being synced after done with moving the throttles.
That, and I'd love to get the device link readouts to let it control my colored buttons on the G940 throttle
Btw, in no case (device link, or the key emulation versions) is power bound to anything under the HOTAS section.
EDIT: What I need to accomplish is a way to get autohotkey read the 'replies' that device link sends when queried. Like asking what the prop pitch lever is set to in the game, and it sends a packet back with a string of text. I need to get AHK to read that info.