No, version 1.3 does not support IRowsetFastLoad. We may add the support in 1.4 and already have a proof of concept.
However, the bulk insert is supported. You can use BULK_METHOD/BULK_INSERT parameters of connection string for fast data load. The Bulk Insert is enabled in Data Link dialog's Advanced page (see Bulk Insert Method=Copy, and Bulk Insert Buffer Size=1000).
Bulk Insert can be used in a Linked Server via Extended Properties of the connection string, e.g.: BULK_METHOD=COPY;BULK_INSERT=1000;
Greenplum/EMC edition of the PGNP Provider supports gpload/gpfdist mode that has even higher performance than COPY due to utilization of multiple Ethernet cards.
For more information see Developer Manual, the section describing connection string.