Handbrake and Dolby TrueHD

[lordhutt]

I'm downsizing a lot of my bluray rips.
I've ripped everything losslessly with MakeMKV.
I want to shrink the size down but maintain the lossless audio.

On my rips with DTS-HD this is no problem. I simply select DTS-HD passthru in the audio tab.

However, on my rips that have only DolbyHD there is no option for this.
I tried the 'auto passthru' option in the audio tab but it does not work.

Can I do this with Handbrake?

Also on the audio... I have a few BD's without lossless audio.
I don't want any quality loss on any of my audio
For example Full Metal Jacket is Dolby AC3 5.1... should I select AC3 passthru for this... I'm assuming when the 'passthru' option is selected it does not alter the audio.

On a couple other notes....
1. Under the picture tab what is the modules option exactly... should I leave it on 2?
2. Without converting 20 movies to compare is it safe to assume that Constant Quality 18RF will be enough to not see any loss in quality....or is this overkill and is 20 enough?
3. I know variable framerate will lower the file size but should I keep constant to ensure quality?
4. Will there be any noticeable difference if I change the Optimise Video setting to any slower than medium?