Hi Jonathan,
Since you are going to use the BP-VG3080ASF on the 3080 ti asus tuf oc,
You can refer to the installation guide of BP-VG3090ASF here.
Please search BP-VG3090ASF or BP-VG3080ASF.
About the thermal pad thickness on the 3080 ti asus tuf oc, it depends on the actual height of the chipsets. You may use 0.5mm, 1mm,1.5mm,2mm, or 2.5mm thickness thermal pads.
https://www.bitspower.com/installation_guide_window.php