Aponogeton Ulvaceus Flowers

Hi, Is it common for Apon. Ulvaceous to send up 3, and 4 flower stalks per
plant in a short period of time?  I have two of these plants and one has 3
flowers that are open and the other has 4 flowers that are open.  These
flowers have emerged out of the water and tank at about 6 or more inches. As
time goes on they have developed prickly star shaped pods?  Should I open
these up and get seeds out to propagate, or is it not worth the trouble?
How do you propagate them? The flower stalks are lasting a long time.  Thank

"There are always exceptions to the rules"