Transport partition using transportable tablespace

Dear experts:

 I'm looking into using Transportable Tablespace to move individual table partitions for backup/restore/redundacy feature in our data warehousing application. Our tables use range-list partition and each partition is stored in a separate tablespace.

Note 731559.1 provides detailed step-by-step instructions. I followed the instructions and everything worked fine: I created a list-partitioned table, and exchanged the partition to be exported into this table, dropped the empty partition, then exported this table.

The only problem is that it won't work if I don't drop the empty partition (otherwise transport_set_check always fail), though from the document it seems that drop partition is optional. According to the Note: