The oven is a bit overdone I think…
If you make a BPM just do it inside with the sensor at room temperatures. Then you’ll need lesser darks for better statistics. This is just how the sensors work, so it has nothing to do with how I implemented this ;-)
Making it at 20 degrees Celcius or hotter will be more efficient than 0-10 degrees Celcius outside.
There is no need to put it into the oven, really ;-) Never done this myself…