Comment 7 for bug 1942260

Have you tried environment variables?

From the xz manpage:

ENVIRONMENT
       xz parses space-separated lists of options from the environment vari‐
       ables XZ_DEFAULTS and XZ_OPT, in this order, before parsing the options
       from the command line. Note that only options are parsed from the en‐
       vironment variables; all non-options are silently ignored. Parsing is
       done with getopt_long(3) which is used also for the command line argu‐
       ments.

       XZ_DEFAULTS
              User-specific or system-wide default options. Typically this is
              set in a shell initialization script to enable xz's memory usage
              limiter by default. Excluding shell initialization scripts and
              similar special cases, scripts must never set or unset XZ_DE‐
              FAULTS.

       XZ_OPT
              This is for passing options to xz when it is not possible to set
              the options directly on the xz command line. This is the case
              when xz is run by a script or tool, for example, GNU tar(1):

                     XZ_OPT=-2v tar caf foo.tar.xz foo

              Scripts may use XZ_OPT, for example, to set script-specific de‐
              fault compression options. It is still recommended to allow
              users to override XZ_OPT if that is reasonable. For example, in
              sh(1) scripts one may use something like this:

                     XZ_OPT=${XZ_OPT-"-7e"}
                     export XZ_OPT

From the zstd manpage:

   Environment Variables
       Employing environment variables to set parameters has security implica‐
       tions. Therefore, this avenue is intentionally limited. Only
       ZSTD_CLEVEL and ZSTD_NBTHREADS are currently supported. They set the
       compression level and number of threads to use during compression, re‐
       spectively.

       ZSTD_CLEVEL can be used to set the level between 1 and 19 (the "normal"
       range). If the value of ZSTD_CLEVEL is not a valid integer, it will be
       ignored with a warning message. ZSTD_CLEVEL just replaces the default
       compression level (3).