This utility is inteded to be used on FreeBSD with if_ixl(4) driver. It disables Module Qualification check to be able use any SFPs.
NOTE: since the datacheet is not clear about the location of PHY capability data structure, I made some assumptions when did the search. If my assumptions are wrong, this can damage your card. If you are not sure, do not use this utility. Also, it looks like the location highly depends from the firmware version.
At least try to use ixl_unlock with -g option and check that all described values are correct.
Currently tested only with 0x15848086 card and fw_version: fw 5.0.40043 api 1.5 nvm 5.05 etid 800028a2 oem 1.262.0