It's an MOT failure and the best way to deal with it is to remove the LSPV forever. This will create unnecessary expense trying to fix/replace in the future, one less point to go wrong, and most of all it makes f**k all difference to the actual braking.
I too thought of doing that originally, glad I never did it, they told me it would fail MOT automatically if there is no LSPV present. They know they're fitted as standard, and say if it was fitted as standard, it must be there and working correctly, or words to that effect. Doh!