I did think about blocking it off but reading around suggests that the EGR does have a function in the engine - cooling the fuel charge for one thing.
The problem I had meant that the valve was jammed shut and was effectively the same as being blocked off as far as I can tell, the result was a continuous MSCF message.
I think I'd want to be a lot more knowledgeable about the inside of the engine before blocking the valve long-term but I'd appreciate an insight
If the solenoid is sticking, its normally because its corroded, so the EGR will
fail again. Minimum you should do is to replace the whole EGR. As others have stated, ideally you should blank it. The only purpose of the EGR is to reduce the burn temperature in the cylinder (and therefore reduce nox).
On the other hand the EGR:
introduces soot into the manifold, (which mixes with oil fed in through the breather pipe) gunking up the manifold, throttle body, inlets etc, this will reduce air flow through the engine over time (and power, worse efficiency), and increase the likelyhood of something else failing.
It reduces the O2 content of the air in the cylinders, reducing the burn of the fuel (as it is supposed to), in the real world it means the burn is less efficient, so less power and decreased fuel efficiency
It also increases soot production of the engine (the soot the EGR allows in acts as a floculant)
It takes the exhaust gases from just in front of the turbo, reducing the boost from the turbo, and decreasing performance (ever have to use the clutch a little more than you would like to?)
Its another thing to go wrong...again!
Give your MAP sensor a clean (it's just next to the EGR valve), this will show you exactly what the EGR is doing to your engine! Cleaning it will also help your engine run smoother.