As of my latest knowledge, SMPlayer does have a specific, dedicated "Wayland feature" listed in its official changelogs. However, here is the relevant context regarding SMPlayer and Wayland:
The most important "feature" for SMPlayer on Wayland is using the mpv backend with Wayland support . SMPlayer is a graphical front-end for mpv (or MPlayer). If you compile SMPlayer against mpv (which has native Wayland support via --gpu-context=wayland or the vo=gpu with Wayland backend), SMPlayer inherits that capability. smplayer wayland