In part mode, the majority of the editing functions (model tab -> editing group) are not available unless you have already selected the relevant geometry beforehand. This should not be necessary and can waste time in some cases. A better approach would be that selecting these functions automatically modifies the selection filter to corresponding acceptable geometry.
For example, to use the extend function I currently need to first select a quilt's edge and then I can click on the function. But my goal was to select all tangent edges using a rule-based selection in the extend function, so I need to go reselect the edge in the function anyway. If I could start with the function, I would save the first selection of the edge. It may not appear much, but it can stack up!