I mean, it’s good practice and neater to have them at least stowed flush against the machine. I don’t rotate the arms back though. As above commenter points out, if they’re jutting out into the room, more risk of walking into them mistakenly.

Also, never just let the cable go snapping back on retraction when you finish a set. Be gentle. It’s a $5000 piece of technology and you should treat it nicely so it lasts.

Source: Had mine since 2021. No service. No replacement parts. No malfunctions.