the bios version is the one saying “project version tpad x.xx”
that number is your bios version.
The mod if you have experience from modding PCs is a 15 minute job. Otherwise take it slow and do it properly. The case is relatively easy to open with a guitar pick or a credit card. Start from the white side where the camera is. Take it slow because there are plastic clips that might break if you force it. The temps will drop about 20 degrees if you do it properly. Maybe more,depending on the activity. For example, while installing updates in windows, the temps would reach 80 degrees whereas now the are 50-ish.
I just got my x98 pro, there is no change in the thermals. But with the thermal mod you’ll see temps dropping by 20 degrees. I did it on mine so i’m talking from personal experience.