If the maintainer does not respond, you may refer to Jakobsen's suggestion [1]:
If the maintainer is not active and does not respond within a week or two then you could mark the package as out of date and then do an orphan request to take over the package.
gnlrdrvo[1] https://lists.archlinux.org/archives/list/aur-general@lists.archlinux.org/message/M7TZTWKHZNOG3AOW76LJQMBUAN6COWM6/