Hello! Recently got my R2 Pro and have carried out about 10 roasts so far. I’ve noticed since the initial seasoning the IBTS reading is now consistently below the BT one. Is the likelihood that this is a cleaning needed of the sensor and maybe because I took the seasoning roasts super dark that has meant it has been coated in dirt / oil? See below for comparison of first seasoning roast vs. most recent roast:
I would definitely clean the IBTS after doing seasoning roasts. It could be buildup, or it could just be a piece of debris in the way of the sensor.
It’s a very simple job that takes less than 5 minutes to do, https://www.youtube.com/watch?v=AkmiZeUKeIA
I would guess it takes longer to make one of these posts!! 
One other reason, apart from what morgan said, which you should absolutely do if you haven’t since seasoning, is that you simply have the preheating temp set too low for that amount of beans. The minimum should be 295°C, but I’d go 300 or even 310.
Definitely try this @adam.cTfR my standard batch size is 775* and the typical PH temp is 280* for me
Thank you everyone - really helpful! I’ll do both of those things tomorrow.