I'm going to add a 2nd Helix to the bow of my 2019 921... I currently have a single plate/bow mount from Precision Sonar.
I would prefer a stack mount because I think it would be easier for me to see and I pitch, flip, skip a lot and think the stack would stay more out of the way. I would just order the Precision Sonar dual stack and call it good, but I'm concerned the mass of two units will ultimately pull the screws of the bow shroud out. I run Lake Michigan occasionally, so it can get pretty serious.
Thoughts and personal experience would be great.