Service based failures questions

I'm trying to wrap my head around the service based failures and have a few questions to ask for some help1) When selecting service based failures (ill abbreviate to SBF for simplicty) to on from the simulation menu in the FMC, it commands all 737NGX aircraft that i have installed to have SBF on? correct?2) Now say i want a particular aircraft to have SBF disabled, when i turn off SBF from the aircraft -> failures menu, it also changes the SBF setting in the simulation menu, thus affecting all other aircraft? is this correct?3)And finally, say I have SBF active and fly my SAS 737 and accumulate 20 hours on it as shown on the maintenance page. Then i fly the same aircraft and do a flight with SBF DISABLED. Now, after that flight i go back and ENABLE SBF for that aircraft, will the 20 hours i previously accumulated still be accumulated on the aircraft, thus the time just picks up where it left off when i disabled SBF? Or will the hours revert to 0 and have the time accumulate from 0? Hope that makes sense. Thanks for any helpAdam Kaleniak