As a Roblox developer, group owner, and player, it is currently too hard to keep group walls free and clean of spam from bots or just certain words in general.
To solve this issue, I propose Roblox engineers develop a few different features to detect and prevent spam along with empowering group owners to prevent spam themselves too.
There is almost no doubt that there needs to be a filter that attempts to detect spam based on whether or not the same message has been previously messaged or contains and unallowed offsite link. Any messages detected as spam by the filter would be held for review, in a tab labeled “Likely Spam” on the group admin page, by a group owner or a user with the power to delete group wall posts.
Group owners should have the power to set blocked words that are not allowed to be posted on the group wall.
Block Links and Hashtags
Group owners should be able to completely block any links and hashtags at all from being posted on the group wall. Any message containing a link or hashtags would be held for review under a tab labeled “Held for Review”.
The features I listed above are all in the YouTube comment section for each channel which does a really well job of filtering out spam compared to most other websites.