If you're talking about reflashing because of Nokia updates, it could be argued that your fears are unfounded. I'm not sure about Fremantle, but with one of the last Diablo updates, over-the-air fixes could even handle the kernel. A reboot was needed of course, but impressive none the less. Regardless, backup often and always keep a good Fiasco image nearby.

But if you're talking about reflashing because of your development. Just what kind of development are you planning on doing that would need a reflash? Inquiring minds want to know.