[HELP] Loss of x264 options when selecting a preset

[The_Tinkerer]

I've always just glossed over this, finally it's bugged me enough to ask about it.

In Hybrid, load any video, go to the x264 tab, and select "constant rate factor (1-pass)" for encoding mode.

The x264 command line looks like:

x264 --preset veryfast --crf 18.00 --profile high --level 4.1 --ref 3 --direct auto --b-adapt 0 --sync-lookahead 15 --qcomp 0.5 --rc-lookahead 40 --qpmax 51 --partitions i4x4,p8x8,b8x8 --no-fast-pskip --subme 5 --aq-mode 2 --vbv-maxrate 62500 --vbv-bufsize 78125 --sar 1:1 --qpfile GENERATED_QP_FILE --non-deterministic --demuxer raw --input-res 1312x960 --input-csp i420 --input-range tv --input-depth 8 --fps 25/1 --output-depth 8 --output "C:\Users\Administrator\AppData\Local\Temp\Lossless.264" -

Now, click the arrow next to "Preset", in my case I use veryslow. The command line changes to:

x264 --preset veryslow --crf 18.00 --profile high --level 4.1 --ref 6 --sync-lookahead 1 --qpmax 51 --vbv-maxrate 62500 --vbv-bufsize 78125 --sar 1:1 --qpfile GENERATED_QP_FILE --non-deterministic --demuxer raw --input-res 1312x960 --input-csp i420 --input-range tv --input-depth 8 --fps 25/1 --output-depth 8 --output "C:\Users\Administrator\AppData\Local\Temp\Lossless.264" -

So, the following command line options have been completely eliminated:

--direct auto
--b-adapt 0
--qcomp 0.5
--rc-lookahead 40
--partitions i4x4,p8x8,b8x8
--no-fast-pskip
--subme 5
--aq-mode 2

Is that by design, or a bug? It's been like that for quite a long time.

Video files seem to look and play fine... so I'm not sure how important this is.