I'm wondering, after searching this forum without any fitting posts, if, one
can make 'HT' rewrite all links to point relatively even if you set the
mirroring depth to only 1. In this way I can update my projects manually and
stay "more in control". 

I cannot find anything in the GUI version that indicate such an option. Is it
possible with the command-line version or is it possible to tweak any files in
the hts-cache folder

I would find this very useful.