While it is sort-of possible, I would strongly advise against it.
You can set your parameters on your Item Card (not SKU), then whatever your main Location is, set it as the "Components at Location" within Manufacturing Setup > Planning (even if you aren't doing Manufacturing). This will force the system to use the Item Card's parameters as the criteria for planning for your main Location. However, it is still only planning for the demand at the main Location, and the other Location demand isn't accounted for.
When you have multiple Locations, you need to tell the system how to replenish those Locations. You can still buy everything to the Main Location AND have the other Location demand accounted for. I strongly suggest a SKU per Location, assuming the Item will go to that Location.
If you set the SKU to "Transfer" from Main Location, it means the other Location's demand is accounted for at the Main Location. Alternatively, you can purchase/produce directly to the other Locations by using any of the other Replenishment Systems on the SKU records.
I would also encourage you to attend the DCI National UG meeting (webinar) on April 16th, where I will be reviewing the MRP capabilities within Business Central:
P.S. "Location Mandatory" should be on whenever you have multiple Locations, and there is an argument it should always be on even if you are a single Location.
Best Regards,
Ben Baxter
Accent Software Inc