Variable formatting of datetime with DateStyle=ISO

Hi,

I just posted a message to the interfaces list about how this is causing
problems in th JDBC driver, and I'm wondering if there's a reason why
the EncodeDateTime function creates a different format string depending
on whether the date has milliseconds.  Would it break anything if it
always returned:

yyyy-mm-dd hh:mm:ss.SSzzz

even if the SS will be zero, and even if the time will is null: 
"00:00:00.00" (midnight)?

Also, why are there only two digits of precision on the milliseconds? 
shouldn't there be three?
-Nissim