There was a very useful paid plugin in the Extension Warehouse called TruOffset, developed by TrueGeometry, that had an additional feature the native Offset Tool doesn’t have (yet) - hole-aware offsetting. The plugin no longer works for the 2018 version unfortunately, giving an error at startup.
Anyone know an equivalent and simple alternative, that would do the job? The window frames I’m currently working on have a lot of openings that desperately scream ‘Accio Plugin’!