That sucks. But I have to say the timing is somewhat fortuitous for the rest of us.
This ridge you describe on the metal insert-- do you think it contributed to the problem? I was considering getting a new flange and immediately replacing the plastic quick connect with the metal ones, making sure they are not overtorqued. Maybe not a good idea?
As far as the availability of the flange, you might check the fiche for other bikes that may use the same pump to see if a separate flange is listed. For example, the 2010 GS uses the same pump P/N as the 08-09, but the flange is listed as a separate part only on the 08-09 fiche. Go figure.
So in my little worldview I have 4 data points. Mine cracked after 3 years. Roy's lasted 3 or 4 years. A friend's 2006 RT cracked right before his 3 year warranty expired. Jim's seemed to have lasted a little longer. Maybe I'll make the old pump into a piggy bank to save for the next one in 3 years.