LOL. Usually with a ride I haven't done before, i'll hold on until I 'get a feel for it' - sometimes thats 2 seconds into the first drop, sometimes it's the 2nd or 3rd ride.
I've ridden Superman Escape many times. I'd never thought to 'not hold on' because of the ejector in the top hat, but I once rode it with @djrappa who lifted his hands above his head pre-launch. Typical ego meant I did it too. The launch then pretty well ripped my arms out of the socket at the shoulder. From then on I learned to brace them bent and slightly forward until the launch had peaked (acceleration force ends around the exit to the building, despite the launch cable continuing for several metres) so I usually put my hands straight up and out as I exit the showbuilding. It makes the ejector something else - especially if you're at the front.
TBH, for me, apart from that one stipulation, there isn't really anything on the coast where i'd 'need' to hold on (Although afterthought - JetRescue also has this initial launch force that you should guard against). I haven't been on the 'new' Cyclone, so that one I couldn't tell you.
I do still find the urge to hold on irresistable on Buzzsaw. Something about those restraints makes you feel the need to hold on.
Just my opinion.