The "Limit" light- at least on the 355- mirrors the servo transparency on the 350. It's not uncommon in flight.
The difference between the two situations is important. In a 350, you have inequality in control forces, and thus compromised control at an unexpected, unplanned and potentially dangerous time.
If you're in the 355, the same situation results in a light on the caution panel, and the controls remain fully effective. Hmm... so much for the blades stall and mechanical control issues....
The airframe differences between the two types are minimal beyond the power plants, electrics, and tankage. The biggest difference is the 355 has dual hydraulics and direct drive pumps. The vert stab differences probably aren't germaine.
My guess is that the servos and the hydraulics just aren't robust enough to overcome flight loads in the 350.
Regarding the hydraulic system circuit breaker- in 17 years I've only flown one (of dozens) that had CB's in place of the factory fit fuses. Remember that it requires electrical power to disable the boost...