SamyGO

as actual workaround you could first set the sleeptimer in normal TV mode and then switch over to media play.
tv will still shut down, but don`t know for the 1 minute warning, think its not shown.
happend to me one time accidentally

i`m using smb share mount on my b650, so it has the wonderfull resume option.
i can stop the movie get out to normal tv, change what i want, go back and play the movie.
while restarting the movie from scratch just one press on the blue key and i`m back where i left

same should work with movies played from usb.

i`m not one of this forum`s genius programmers, but i think adding the options you seek for to the mediaplay menue is littlebit
difficult if the options aren`t allready present but just disabled.