Mods should be able to switch from opt-out (manually remove Mastodon posts from the hashtag-community) to opt-in (manually "boost" Mastodon posts into the hashtag-community). That switch could also flip like a fuse when a threshold is reached, with an admin-configured max_toots_per_day.
The flooded mod tool could help itself with filters by min_boosts, min_stars, links, media and max_age, etc.