Watching the video again, I think I answered my own question: it seems like they will pay you rewards on any USDB balance over 10 USDB on a spark address. Since USDB seems only to be issued on Spark, this means they pay rewards on any USDB balance over 10 USDB.
Watching the video again, I think I answered my own question: it seems like they will pay you rewards on any USDB balance over 10 USDB on a spark address. Since USDB seems only to be issued on Spark, this means they pay rewards on any USDB balance over 10 USDB.