Even though in some peoples opinion they sound daft, would i have any long term running problems if i was to fit the following BOV to me car 95/96 import sti.

Bailey Motorsport Twin piston Dump Valve DV26

Also same with the dawes device any long term running problems running this and will i notice the difference in performance of the car with it fitted.

I would also fit a knocklink device and a AFR device boost gauge already fitted.

last question i running optimax with wynns octane booster is this stuff ok long term or shall i use a different kind of octane booster this is most important to me, don't wanna do any big damage to me pride and joy.

Thanks in advance
A.N