I find using constraints on the end points of lines largely removes any need to trim them. For instance, a coincident constraint for the ends of a line and an arc, then a tangent constraint between them will only require a couple of dimensions to produce a robust part that is actually what you thought you’d drawn.
Surely Atom allows you to turn toggle the visibility of construction lines? Although needing to do that to reduce clutter is a good indication that one complex sketch might be better split into several simpler ones.