No one knows as no one has tried as it just may result in a brick. Why even chance it when flashing back to OFW then formatting and going back to CFW only take an extra 10 minutes. That is my suggestion unless you have a PS3 to spare and would like to be the guinea pig.
PS3 CECH-2501A [CFW] & CECH-3001 [OFW]/ PS2 SCPH-3901 & SCPH-7501/ PS Vita TV PCH-1000
MOD Custom Cobra 4.46 v7.00 w/ E3 Flasher [CFW] & Cobra ODE 4.53 [OFW]/ Mod HDD-OSD [Phat] & Modbo 4.0 [Slim] / FW 2.60 [TN-V]
HDD 1tb [CFW] & 640gb [OFW]/ HDD 640gb & OPL v0.92 w/ 1.5tb SMB /Memory 8gb & 32gb