Exactly the reason to create that other topic, because being able to know the deviation before completing a command that modifies or builds a surface is essential.
As for the complexity of trimmed edges, the VSR plug-in for Rhino 5 had a tool to simplify and re-trim them based on user-set tolerance. I forgot the command’s name (“Edge approximation” maybe?), but those with VSR should be familiar with it. It’s a fantastic way to reduce the control points of the nearby surfaces that need to be matched to a trimmed edge, including “Blend surface”.