Thanks for your post, i love that kind of post
I think you don't have to upgrade the firmware because you have the last one ;-)
When you power on the PreenFM, you should see 1.50 somewhere. If it's the case, you are up to date.
1.50 is the same as 1.50.Beta4.
I will make a official annoucement next week, when all the kits are ready to ship.
Congrats for the fast build.
Enjoy your new sound module, and don't hesitate to share your patches ;-)