it's that 100%
It will fix with a different sensor like 3bar,
but you can keep stock sensor and he can keep using latest racerom 12.1 but ask him to only use maf
Even if he enable hybrid speed density but actually use only maf, it will cause the bug
Now the switch to total maf will throw off his tune work
))
He would need some revisions at least, to make a good job
Just for your info, I think they use speed density because they set the curve the same for each car, so they have same engine load in each car and don't have to retune much. They let the ecu correct the AFR mainly