Use an arm to hold the transducer center of hole and deep enough to only remove the air.
Or if someone is say on your left, instead of center of hole have it on left side of hole.
This helps the ice to reject some return signals from unwanted sources.
Also use narrow beam if you have it when your in that situation.
If you hang it below the ice, it can pick up other sonar return signals easier. It's easy to get tangles while landing fish.
I've seen aftermarket arms built. I've seen someone use two box end hand wrenches. Marcum makes one for their sonar.Vex had an eye bolt arm, non pivoting.