hi mate i new here and this is my take on this subject
removing or blocking the EGR is not a performance mod !! it only works at cruise and it lowers the cumbustion chamber temp to reduce NOX "nitrides of oxygen" a very silent killer if it leaks into cab!!
the sooting is a by product we have to live with ,it is a polution control device and ""ILEAGAL" to remove or modify the same as removing a cat converter$10 grand fine if caught!!
so if you leave it there it already is a performance mod ! well kind off lol.
so in a nut shell , if i cut ur arm of ,you can live without it cant you ?? but if it wasnt ,it would be better !!