Customising the Welcome Message "You've Joined the XXX group"

I've seen the thread about turning off the message for new members of the group.  I'd like to tweak the message, in particular to change the "View and Share Files" link to be a different document library than the site default documents.  We don't use the default doc library as a rule but it ends up as an accidental repository because that library is the default in messages, saving, etc.

It would be really great if there was a way via the UI to customise the URLS in the default message, as well as pick and choose which apps are featured.

Any thoughts on how we may accomplish this? Thanks.