If I understand your description correctly, I think there's a way to
simplify the process.
This would be to create a sketch as a collection of location points to
be used in developing a Sketch Driven Pattern.
When the pattern is defined you can use a single pre-existing Hole
Feature (Cut-Extrude, Simple Hole or Hole Wizard type) to automatically
populate it with the copied hole axes centered on the point locations.
If all 50-100 holes are not the same, then you'd need a separate sketch
for each Sketch Driven Pattern definition.
Just as in the "reference" sketch you described, there would need to be
an entity to use in keeping track of the scaling. There's no need to
use any in-context conversion of a hole diameter - a construction
circle dimensioned to be a starting unit of "1" (inch or mm, etc.) will
After the Sketch Driven Pattern is defined, simply use the Tools/Sketch
Tools/Modify function to execute a scale change. The original reference
circle of "1" unit will become .5, if the scale is made to be one half.
After the first scaling, the reference circle will report a dimension
of ".5" unit and, if the sketch is scaled again, changing it back to
full size ("1" unit) would of course require a scale factor of 2 and
setting it to be 1/4 of the original "1" unit would require a scale
factor of 1/2.
Keep in mind that, in order to scale a sketch, there can be no external
references. This means that it may be necessary to fully dimension the
point locations (instead of using relations) and to delete the X and Y
dimensions which locate the entire pattern of points. After the scaling
is applied, the X, Y dimensions to the origin of the point patttern can
Hope this helps...
Per O. Hoel