Yes, cut off all the upright growth. That is pretty much the only pruning double file viburnums need. I just did that to my young 'Lanarth'.

Thank you

Last year i trimmed all the vertical sucker growth out of our Shasta doublefile viburnum. it did not grow any taller. I’m trying to get them to get taller. I was thinking of letting the suckers grow this year. Has anyone done this? I’d like them to get as tall as possible to block the road without sacrificing their shape.

Thank you

Double file viburnums, whatever the cultivar, are pretty much a good deal wider than tall, and the horizontal growth is an integral aspect of the plant. The vertical suckers still should be pruned off because they ruin the shape of the plant. Research the size of your cultivar.