[yocto] DISTRO_FEATURES_append, anyway to override?

[Hans Beckérus]

We are using a user defined distro, based on poky-tiny. That is, we
'require' poky-tiny.conf.
It is done this way in order not clutter our distro configuration with
too much magics and defaults.
However, one problem now is that poky-tiny also 'require' poky.conf,
and implicitly is doing

DISTRO_FEATURES_append = " largefile opengl multiarch wayland"

In our configuration we do

DISTRO_FEATURES_append = "nfs"

The resulting DISTRO_FEATURES (as checked by bitbake -e) shows that
everything appended by poky is also added to the custom distro.
Now, we would like to remove everything but the large file support as
added by poky. How do we do that? Is the only practical way to copy
everything from poky.conf and poky-tiny.conf into the custom distro? I
really would like to avoid that if possible.
I guess that the new feature DISTRO_FEATURES_remove might help us
here, but unfortunately we can no step up to such a late version in
a foreseeable future.

Thanks.
Hans