We compile the source code for Dolphin builds on this site as a convenience for users. Our policy has been for quite a while that anything older than the latest stable build is unsupported on the forums. Simply because old builds are still available for download does not imply we still support them. That sort of thinking is based on assumptions.
Even though 3.5-xxx builds are not supported, there's really no valid reason for stripping them from the Download page, especially if you consider archival purposes or regression testing.
Even though 3.5-xxx builds are not supported, there's really no valid reason for stripping them from the Download page, especially if you consider archival purposes or regression testing.