Always… the user must choose to advance on this matter, has the abilities to recover a death motherboard, have backups of the Bios and/or have a SPI Programmer and experience with it. Usually when they got lucky on a mod, its all-sweet form there…wrong, it can happen on a next attempt and to all of us.
The updated bios could have limited/removed the OC ability and/or the cpu mcodes that the OEM had updated in the bios releases.
There’s old mcodes that can be inserted back in bios image or you can downgrade the bios version, etc… this is all actions with certain risks and no one can assure you of anything.
This is a board with no dual bios or bios flash back feature…
[Guide] How to flash a modded AMI UEFI BIOS - BIOS/UEFI Modding / BIOS Modding Guides and Problems - Win-Raid Forum (level1techs.com)
Normal Asrock flash procedures can fail (security issues) due to modifications in bios image (mods…)
So several methods may be needed and not all possible (Bios Security Locks)
So general speaking… this is a bit time consuming from the user side, requires a bit of experience and the risks are always present.
Other similar cases, users had some success in cross flashing bios from the vendors, ex. as in your case, forced programming the Asrock B250M-PRO bios in your B250M-PRO4-IB motherboard.
You may wait for other users pov and maybe @chinobino can give you a hint about the mcodes, good luck.