With a quick disconnect, you have removed the source of concern: water tracking up the hose due to the floating seat and into the first stage. If you disconnect your SS1 from the bcd hose, it's perfectly okay to soak in fresh water.
A 2 year service interval is more than reasonable, IF you rinse the reg after every trip. SS1's and Air 2's and AirSource regs are notorious for corrosion, but mostly because they're left damp on the bcd after a saltwater dive. If you disconnect and rinse them like your primary second stage, the seat can last more than 2 years easily. However, it is probably worth dropping by your LDS to have them retuned yearly. They are downstream second stages, and the floating seat carrier can rotate out of adjustment over the course of a year's diving. But that should take no more than 10 min work, and a minimal charge.