I recently suggested something very similar in the Cura forum.
However, it's not just about the angle it's also about fine structures.
An edge detection algorithm could run and look for fine structures in proximity.
When the layer number approachs that area the layer height gets reduced step by step
Once it's past the area the height is increased again.
The speed of increase, reduction as well as minimal and max layer height should be configureable.
That would be a HUGE step forward in print quality vs speed. It would mean best possible quality with highest possible overall print speed.