All 4-Wide 4-Residual Patterns
In 4-Wide, having 6 residuals has the greatest combo potential, followed by 3, 5, then 4 residuals. Read this article for more information.
This is the most challenging residual type to maintain, but it is the only residual where you don't have to soft drop any pieces (except for 2 cases, which would account for less than 1% of the line clears). The MisaMino bot most notably uses 4-residual.
4-residual can be artificially set up by dropping a mino on an empty four-wide well. The video below shows an example of amemiya (あめみや たいよう) doing it.
credit to Okey_Dokey for the 4-Wide 4-residual base data. credit to mat1jaczzy for the MisaMino tidbit