Currently we have been using RowVersion in our tables for concurrency with stored procedures. The problem that I'm trying to solve is that many users may be updating the same entity, but different parts. I tried using the DynamicSQL and it builds the SET statement for only changed data, but the where clause contains PK or PK & RowVersion. Is it possible to get the DynamicSQL to build PK & Changed Fields in the where component?

No, ES will not do that, you're wanting field level concurrency and we really don't support that. Do you really have so many concurrency hits that this is a problem? That would be somewhat unusual. However, ES doesn't build update statements like

WHERE @PK=PK AND @LASTNAME = LASTNAME AND @FIRSTNAME=FIRSTNAME

We will enter this into our tracking system however to be considered for a future release.