While analysing a part in Simxpert that one has drawn up in an external CAD package such as Inventor, is it possible to go back into Inventor, edit the part and then snyc the changes in Simxpert without having to export it and start the whole process over again in Simxpert?
Not with Inventor files, only with Catia, NX or ProE.
Can't you make the geometry changes in SimX, or why not record a Macro of the process?
Macros are also called Templates and can be saved in the tool ribbon under the Templates tab.
Start recording one with ALT+R or Tools>Macros>Record new Macro.
It saves a PROC file by default in C:\Users\(your username)\Process\Recorded
If you move the PROC file to the ...\Templates folder, it will be selectable directly under the Templates tab in future SimX session.