Hi Alan,
Yes that works perfectly well for regular curves but, being a bit of a perfectionist, some of he time I need irregular contours for these arcs. In these instances I prefer to build a custom part and import it. You have no loss of function and it is far faster than fiddling with the hole punch (In envisioneer or ca or tfp) Envisioneer does have rather basic drafting capabilities so inthat instance you can adjust arcs in this manner however, it is still slower than sketchup. To be honest, sketchup is a fantastic addenda to tfp or any other design program which can import its format/files. Simple, quick and convenient.
Not sure if you have tried it yet but it is a boon and if using the free version your outlay is purely time.