Hi

i am just a everyday person. not doctor or research. just add some experience and thought.
i often notice a single flinch in my legs as soon as i am near sleep. but no knowledge of RLS -
i sleep alone.
however was once plagued by nightmares and my whole body reacted and woke up stressed and sweating.
after many months of intensive practice of lucid dream control, i did reduce the intense dreams and fear. l learned to fly away in my dreams . so did not feel trapped in a stressful dream.
maybe this can help ???
i had a friend sleep over, her legs moved when she was dreaming. when i calmly talked to her it
would stop and she stayed asleep.

i do often play disc golf and feel my arm moving while sleeping.
just a twitch, but definitely related to the game play motion. sometimes wakes me.

so i am aware of the connection between dreams and actual body motions.

i also am adverse to medications. i prefer foods and TCM.

maybe you can get some relief in lucid dream practice, dream journal - to gain awareness and sone control.
hope you find relief.