DRD compactor versus stdcells

Is it possible to use the DRC compactor to take a row of placed standard cell instances and shove them all up against each other so that their individual prBoundaries just touch?  Or is this the wrong tool for the job?  In the DRD Compactor Options form I've been using

Compaction mode:  compact & spread

Anchor mode: use last shape in direction of compaction

spacing options:  I've tried various things but it seemed like User spacing=0, apply to active layer in palette, and select prBoundary in the palette.

I've also tried M1/drawing as the selected layer since M1 power/ground rails run right up to the prBoundary on the stdcells too.  But... I can't seem to get the thing to work.  The tool seems to think for way longer than it should (I'm only trying to close the gap on maybe a dozen instances) and it doesn't actually get the cells abutted the way they should.  The gap is reduced but not down to the level it should be.

I can get the compactor to work on some of the examples in the manual of compacting wires but just not instances.

Any suggestions?  Surely I don't need to write custom skill code for this.

Thanks

-Dan