We've recently gotten a few reports of screws rattling loose during shipping and anything that's gone out since then has blue threadlocker on the screws. There's already a version change in planning to improve heatsink screws and ease of getting the case on and off.

It's not advisable to use thermal compound on the top chips or we would have done so. The IC package is plated and electrically connected to local ground, which means that unless there's electrical insulation between the package and heatsink, you can cause shorts and break stuff. We use a 0.5mm 20W/k silicone pad to avoid shorts.

I'll do some testing with adding TIM to the underside heatsink and see how that changes heat management.