Is there a retailer for DIY’ers that sells a microcoil comfort layer?
Hey Spoonman01,
Welcome back and thanks for your question:) .
Microcoilsas a consumer DIY component are not readily available. Have you checked with trusted member Arizona Premium Mattress, @KenHightower? He had worked with you previously regarding L & P pocket coil arrays , maybe he can point you in the right direction. Otherwise, many coil arrays, as well as other components are in short supply due to COVID-19 related production slow downs and record-breaking holiday ordering. There will likely be a bit of a wait before some special order components are readily available for direct-2-consumer purchase. Let us know if you do find a resource in case other consumer DIYers are in the market too 
.
Thanks,
Sensei
THX!