How to replace package in system configuration?

[Jone]

Hello. My question briefly: I want to get a compact base system, but can not do this by of the dependencies.

Now for more details: during reconfigure installed a package A. A depend of B, B depend of C,
C depend of D, .. and all of them I don't need.
Removing package А will probably require a lot of work, but I can change the dependencies of the package

and rebuild A at next reconfigure. But how to specify it in system_configuration.scm?

Such variant:

    (define-public PKG-A
     (package (inherit PKG-A))

     (name ...

     (version ...
     (arguments
       #:tests? #f
       #:configure-flags LIST-OF-CHANGED-CONFIGURE-OPTIONS
       ...

- probably is wrong? Then maybe so:

    (define B
     (package (inherit PKG-A))
     ...
    (define-public B)

In my case, the unfortunate chain of dependencies is:
    mariadb <- qtbase <- qtsvg <- python-pyqt <- hplip <- sane-backends <- colord

and colord supports "--disable-sane" flag.