Hi ​@ksjohnson,

Yes, you can convert a polygon M (assuming you mean measure values) shapefile to a polygon shapefile. FME provides several transformers to handle M values, such as MeasureRemover, MeasureSetter, and MeasureExtractor, which are readily available in FME Workbench. Additionally, there are more specific transformers available on FME Hub.

Once you’ve processed the M values, you can write the result to a shapefile using a ESRI Shapefile Writer.

Hope this helps!

Emma