It varies, if the apps freshly loaded with nothing playing it can start instantly. If I’m switching between albums its around 20s (21s seems to occur most often).
If I flick between devices (MPD to OpenHome) with a track playing it won’t always play despite the track time counting.
Can’t seem to seek forward/backward while a tracks playing. It either restarts, hangs or picks up at some point in the track with a lag.
Seems pretty robust if left to play an album.