Struggling with Dogwood — would appreciate advice

I want to be honest: I'm not getting great results with Dogwood and I'm not entirely sure why. scale insects or aphids in the canopy attracting sooty mould has been a recurring problem despite my attempts to address it. I've been focusing on formative pruning in the first five years to build a clear leader based on everything I've read.

multi-decade investment that improves year on year is there in glimpses, which tells me the plant has potential in my conditions. I have it in a small garden with a compact or columnar variety chosen for scale which might not be ideal. bare winter silhouette revealing branch structure and bark showed some improvement. Two stars for now — not the plant's fault, but not a success yet. I'll update if things improve.