gbp --filter vs. uscan filtering, pristine-tar

[Felix Natter <fnatter@gmx.net>]

hi,

The java git policy (https://wiki.debian.org/Java/JavaGit#Import_upstream)
tells you to use "--filter ..." during "gbp import-orig" to filter
non-dfsg content. However, most mentors tell you that this is uscan's
job (or the job of a uscan download-postprocessing script) [1]

--> So am I doing something wrong if I import an new upstream version
with
   gbp import-orig --filter foo.txt --pristine-tar --filter-pristine-tar\
   <src.tar.gz>
(or simply "gbp import-orig --pristine-tar <src.tar.gz> if nothing is to
be filtered)
AND
filter the uscan download ([1])?

OR shall I better filter the uscan download and import that?  (I guess
this would break "pristine tarballs", which is ok for filtered sources?)

Does that, in conjunction with "gbp buildpackage --git-pristine-tar ..."
suffice to create "pristine" uploads?

(I am asking because it's a lot of effort to go back to a previous rev
and reimport upstream sources, that's why I develop experimental
packages on a private github repo)

[1] You can specify "Files-Excluded: ..." in debian/copyright and 
uscan will pick this up and filter+repack the downloaded file, see:
https://wiki.debian.org/UscanEnhancements

Sorry for the long text.

Thanks and Best Regards,
-- 
Felix Natter