Some Shipstation users use Fedex Freight exclusively. We're one of them.
It would seem like an easy step forward would be to enable Fedex LTL
shipment through the Shipstation interface.
I suspect a majority of your customers ship a blend of DTC and off-line
stores. The off-line business is significantly more efficient using LTL
shipments, in particular when parcels are larger/heavier. This is a
significant missed element of function...