(adsbygoogle = window.adsbygoogle || []).push({}); will an e3 flasher successfully downgrade 4.75 to 3.55?

If your ps3 is able to be downgraded then yes.

I have a phat ps3 so if I update my ps3 to 4.75 an e3 flasher will be able to downgrade it?

Depends on your fat model with an E3

No it doesn't? All fats can be downed

Not with a E3 No, some Fat ps3's have a NOR model chip on there motherboard... some fat ps3's have a NAND chip which needs a Progkeet or Teensy++ which i believe requires soldering.

The ps3 was originally modded with an e3 flasher. It was running 4.70 CEX, Multiman, and patch. I just don't want to have to keep having another modder flash my ps3 if I accidentally hit the update. I was going to buy the flasher if it will work with all future OFW versions.

What is the model of ps3?

All future versions...that cannot be confirmed,hardware devices such as E3 may OR may not be patched in the future.
But for now,E3 will work on all NOR compatible models :-)
If you keep up to date with the latest compatible spoofers for your specific Cfw you should never have the issue or concern of " updating your system to ofw " :-)

gracias