A bit of a late reply to this, I was temporarily “separated” from my laptop.
Taking inspiration from your approach I ran a bunch of tests on the fan behaviour and I believe it’s unlikely to be due to any changes in 3.05. I saw a few other threads, even with 3.03, mentioning the fan behaviour, so I thought I’d do a write up in a separate thread to keep things more consolidated.
My experiments appear to match your results. If I get a chance I will revert to 3.03 and have another go, purely out of curiosity, but thought it might be best to keep any discussion in another thread that is independent of the BIOS release unless an actual regression can be identified.