I've got the cheapo TCs from Sweet Maria's. Both of them with bead probes.

They are both dropped through the chute, but they hold in place quite securely (a double twist on the heat shield "wires" and bends made at the appropriate spots make them "tight"). The bean mass probe is about a half inch above the drum bottom, and it gets well buried by the beans at all times. The environmental probe extends from the bottom of the chute pretty much straight out, with a slight bend to the right (if you were looking through the window up front), extending about an inch into open space).

I do my own logging of both probes at 30 second intervals. The times on my charts are the times shown on the Hottop timer, hence the countdown.

(Been out of town over the weekend, so need to try the BMF now as drip and as an SO to see how it is now at its peak. This afternoon, for sure!)

Hmm... Maxwell has a higher preheat temp but I've seen some of Max's high temp starts still show this 1 minute to turnaround. Do you have a bare tip probe in the bean mass as well Max? Batch sizes are the same(?) I'd like to understand why this difference....

As aside on preheats in general and 'stored heat energy' in the roaster; Note the rapid rise in preheat temps. The measured ET is likely way ahead of the metal mass of the roaster here. The drum, the casing and everything that heats up from being connected to it. There may be some benefit it taking more time to allow this mass to heat more evenly to the charge temp. This effect may be noticed if you do back-to-back roasts without the roaster cooling down completely. Same ET at start but less energy required from the heater to get the same rate of rise in the bean mass. ( I somehow doubt this has anything to do with your faster turnaround though....)