Summary report w/multi-select field

A low tech solution is to use a Dynamic Filter on that Multi Select field and it will allow you to isolate a single technician at a time.

Another solution is to change the the concept of a Multiple Select field to select the Technicians,  to instead have a child table of Assigned Technicians.  You can still roll up a summary of the assigned technicians using a Combined Text Summary field to the parent Work Order record.

Then you look up the Work Order hours down to that Assigned Technicians table and run your reports there.

The last option is a bit more complicated to set up is that you would have a Pipeline that would create Child Assigned Technicians records whenever the assigned technicians in that multi - select field was changed