Yep. This is the only workaround. But monitoring the float track is not reliable as it can skip over the number, then you have to give it a tolerance which can also lead to other problems.
Another solution would be if there was a way to synchronize Event track inside Timeline with any other track inside the same timeline. But now the only thing that Sync button does is syncronize the View.
Event track just fires out of the Event Pin, each time any Key (no matter the value) is reached in the timeline.
And you can already do that manually, you can input any custom curve and it will work. But feeding it from the outside does not work.
You should be able to Set it as you can any other type of the track, imho.
Or at least in should override with the Set Float Track option while using Event track name.
When you try to export the custom Event track in to a file, it actually creates a Float Curve Asset.
Feels like this is a bug or minor oversight, cause nobody is using Event Tracks. 