After the first segment; all flights MAY be open.

While OPEN segements can apparently be done with e-tickets it may not be straight forward and seems to confuse some agents/GDS's.

I finished a LONE4 two weeks ago, this was ticketed in August 2009. FOr the post August 2010 segemnt I used "dummy" dates.

As these segement became available to book, I simply revalidated the booking as appropriate, while keeping the orginal routing with all transits and stopovers intact.

Booking through AA was great as there was no service fee assessed each time I revalidated.

You could ostensibly, book a three segment routing that meets the fare conditions and then pay the USD125 re-ticketing fee (+ tax difference) each time you add more segments. The way I describe above is generally less costly.