Suggested this for Mlem, but with blocking being implemented directly by Piefed, perhaps this feature would be better suited here.
A major feature that was exclusive to Arctic app for Lemmy was the ability to use regular expressions in filters. As there may be several variations of a phrase one may wish to block, regex facilitates doing so without an excessive number of filters.
For example, this filter blocks a variety of related posts:
[(Google Play|Microsoft|IndieGala|Epic|Itch(.io|)|Prime(/(Epic|Legacy|Microsoft)|)|Steam/Fanatical|Fanatical/Steam|Forever-Free Friday)]
The above would otherwise be 13 filters.
This would be even more useful for URLs:
(biggovernment|breitbart|cbsnews|daily(caller|signal|wire)|decider|fox(|10phoenix|10tv|13memphis|13news|2detroit|26houston|28spokane|32chicago|35orlando|43|59|5atlanta|5dc|6now|7austin|8live|9|baltimore|la|news|weather)|(info|news)wars|justthenews|myfox28columbus|nationalfile|news(max)|ny(post|sun)|oann|pagesix|panampost|prisonplanet|rasmussenreports|rightjournalism|the(federalist|fp|grayzone)|townhall|unz|washingtonexaminer).com
Listed separately, those filters would be difficult to manage, and potentially less efficient.