My car had a little more vibration at idle when the a/c compressor was engaged. After I added the cp-e RMM, the a/c vibrations were much more, but only slightly more when the compressor clutch wasn't engaged. But you're right, it is only at idle... otherwise it's not noticeable. I'm still trying to find my personal NVH limits in this car and have a ways to go... and it's still much less NVH than my other carfrom my experience...there is less NVH in warmer climate. ac doesn't encourage more noise. (initially when you turn it on...it vibrates some....but soon as you start driving, it goes away).
i usually dont hear much until the outside temp dips below 55f. then the dash starts to rattle some.
i have cpe pax side and trans mounts 70a...with boomba 80a rmm