Idk what youre trying to ask exactly but ive found the only thing that needs done to enable controlled lambda >1 is change your "lambdiag" value to whatever lambda you want to cruise at and raise lamlgmtm. No need to trick the ecu or sensor in any sorta way, although you might just want to disable open loop for low loads with RLLRUN if your ecu uses a narrowband sensor but maybe itd still be helpful to have narrowband lean adaptations, idk try it if you have a wideband gauge.
Trying this on MED 17.5.2 Wideband, but did not found "LAMBDIAG" map name, only similar map i've found was "LAMHAP", are this equivalent?