I recently got the ASUS BW-16D1HT with firmware 3.03 manufactured October 2018. And I have found out an interesting thing. This particular drive does not allow burning at lower speeds than 4x whereas my older 16D1HT as well as Pioneer 209-EBK both bought mid 2016 allow burning at 2x.
But what is even more interesting is that it seems like using the latest ASUS with 4x burning speed gives better burns than those older ones at 2x! I am judging from the fact that reading the BD-Rs burned at 4x is always done at “max read speed” whereas on those 2x burns in most cases the drive was locked to slow reading speed throughout the first half or so of the disk and jumped to “max read speed” only in the latter section of the BD-Rs.
This is really something I was not aware of and it really seems like using the lowest possible burning speed (2x) on those 2016 drives was perhaps not the best idea. At least as for the single layered BD-Rs (Verbatim 43804 HTLs to be precize).
The question is if this would still apply for multilayered disks like BDXL for instance…