interesting teardown, thanks.
for homelab application where extra space & power consumption is not a real concern, "temperature resistance" (tempco) is no longer relevant. you can get a constant temperature controller with +/- 0.01 degree range kind of spec for $65. verified using a reputable digital temperature sensor (outside the control loop) and the performance is pretty solid.
out of interest, what would the physical setup look like? Hard to imagine you could achieve isotropic temperature approaching +/- 0.01 degree over the size of a typical PCB.