No you won't have to reinstall the .29 update again, that's set now. Must say I was tempted to use a backup from my L1520 when originally setting up my L950, though glad I didn't as I've heard that those backup's may corrupt your installation on your new phone.
To be honest, this is just my thoughts on the matter, I would do a factory reset, and start a fresh. I know it's a pain in the butt, but it's probably the best way to go. Then once you have your phone set up how you like it, set your iris recognition up again, and see how you go from there. Good luck, and keep us all informed as to how you get on.