I would consider it safe
and will be flashing it to my Sapphire Fury Tri-X STD edition
). Only flash to one bios position so you have other position to recover from.
In the context of your question when comparing STD edition bios vs OC edition (stock PL) there is only changes in:-
FirmwareInfo 1 hex value 02 vs 03 (this table in Hawaii was ignored for any mods as nothing much going on).
PowerPlayInfo have increased GPU Freq. 1000 vs 1040 and 2 unknown hex values at present.
All IDs (DeviceID / BoardID / SubsystemID, etc) are the same between them.
OC edition (stock PL) vs OC edition (increased PL) only changes in:-
PowerPlayInfo by 6 values , 5 of them I currently think maybe fan or temp related and 1 is defo related to PowerLimit.
I did mark PowerPlay way back 07/11/15
and plan to first concentrate on this table first for mods.