Considering that the future gameplay of PGR will focus on team rotation because of the Amplifiers, I wish we could get a better display of their class passive duration than the ones we currently have in the game (as most of the visual effects can easily get buried during an average playing session).
Since Amplifiers show their full potential when accompanying other units, why not put some sort of timer around the QTE buttons when an Amplifier is included in the team? I made some (really) poorly edited examples to show some ideas:
The first example is a time bar that would gradually deplete and change its color after the 10-seconds mark passed. It could be an hourglass or anything minimalistic to avoid clutter, of course.
The second one would be marking the time limit on the QTE icon of the last unit that gets switched out. Given that the swap cooldown is 15 seconds the QTE icon can consistently be used as a time reference (10 seconds is ⅔ of the circle) so reinforcing that with some wedge in the rim also seems like a good option.
The playerbase can get used to the 10 s rotations without eye-catching visual cues but I believe that implementing something to help with it would be a nice QoL change.