With the heater off for repair, I added a strip of self-adhesive stainless steel tape to the top of the plywood platform, directly under the heater. This should reduce the wood temperature and maybe, just maybe, reduce the thermal expansion that shifts the X axis location of the Z-minimum platform height switch.
It’s stainless steel because that’s what was in the Tape Lookaside Buffer; a hunk of aluminum tape, even a pair of 2 inch / 50 mm strips would work just fine.
Not shown here is the M3 screw through the front-center hole (invisible under the tape) that will eventually anchor the new heater connector.
The Smell of Molten Projects in the Morning 