I have fought and fought not being able to turn off flor lights for years. Added the XPF (which tends to catch fire here and burn the wall studs - but that is another story), switched to the good 5 & 15 amp smart home filters, bought the nice code reader to see codes on the line and noise levels, but still fought the darn lights not turning off.
On a whim this weekend I decided to try TWO filters in series - BAMB! Lights turn off now!
My code reader thing shows like 50mv of noise with the lites on and no filter, and 5-8mv with a filter; instructs with it says anything below 10-15mv should be ok - not so here. I doubt I can make a reliable reading of noise with 2 filters in series as it will be down in the 4-8mv noise that is everywhere anyway.
Soooooooo, the moral of this story is GO FOR IT - if you have MULTIPLE (I have 3-4-5-6 depending on location) florescent lites on ONE lite module, and they turn on 100% reliably but have trouble turning off, consider plugging a filter into a filter for 2 in line with the lites.