Have never had a heat problem with ceramic caps, would think even with ground connection on bottom of board heat will travel to them anyway. Likely get by with loosening a bit, but short traces are important. Ran common ground around the outside on one of my TPS chips and it did not regulate, have not done a TPS54386 tho. I look at my etched board with a microscope to be sure there are no little bits of copper between the leads, biggest problem I run into.
RD
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RD
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