Hey no problem:
Once you load the groove that you want, you can apply it as many times as you want (the loaded groove is remembered). You might be able to save your template project with the MPC 50% groove loaded so that it's ready to be applied every time you open your default template...
In this demo I'm loading the groove and applying it to midi items using the Actions window, but you could do the same thing using keyboard shortcuts or from a toolbar:
On a side note: MPC 50% appears to be doing straight quantizing unlike 51% and up which appear to be working correctly. I wonder if that's just an issue with my groove file...