slack should sync these files just fine. I have a couple of roles
with dotfiles in them (for root's $HOME, for /etc/skel), and they sync
just fine.
The slack-sync backend does pass the --cvs-exclude option to rsync
when pulling stuff down from the master, but that only excludes some
specific dotfiles (see the man page for rsync for more info on how
that option works).
--Alan