Roasting from cold/hot start?

[Bean there]

The recommendation is to leave your roaster on, when doing more than one roast session. And if you do turn it off, leave it off for a couple of hours before doing another roast.
Why does it matter, since the probe is measuring the temp in the chamber? (i.e., whatever temp the probe registers will determine how much heat the roaster needs to apply, right?)
I would have thought more accuracy is to be had starting with a “cold” roaster, rather than a heated one that has just finished one roast & then goes on to do a second & third roast… but, we are advised to leave it on.
So, what am I misunderstanding?

[BenN]

Roaster will measure reference temp (ambient) at power on.
If you do back to back roast and turn it off in between, the subsequent session has higher reference temp.

I think newer firmware has some thing that holding previous ref for short time.

However it's safe to make it rest for long or set it manually ( can't tell from top of my head but please refer to manual for how to.)

I think it does more effect on a cooling cycle, but I never know exactly.