This is an interesting theory especially after what happened to me last night. At first, and kind of still now, I thought it was a glitch but I didn't know about that part of the grimoire card. We were doing Atheon and glitches were happening left and right but one time after I came out of the portal and had time's vengeance I noticed my Mythoclast wasn't firing. I messed around for a little bit, switched weapons etc, but it still wasn't working, until I held the trigger instead of single pulls. It started firing like a regular fusion rifle, with a charge time. Don't know if it's something to look into at all could just have glitched out on me.