I struggled with fungus issues on Malus and Prunus for years, can confirm Bonide Infuse works, I apply to soil surface just before bud break and again before post hardening off pruning if applicable.
It also seems to really help prevent needle cast on Pinus if applied before the spring growth...
FWIW my only Engelmann's new growth is always blue for 1-2 years, mine can't possibly be CBS as it was collected in WA state.
Really nice job on the styling Danny