It will pass the emissions test as that checks CAT efficiency and you still have primary main CATS (DPs).
There is no physical test for OPF efficiency (same as diesel DPF has no test).
The iffy bit will be the "visual check" that all emission control equipment is in place. Very much depends on how friendly / daft the MOT man is. Take it to little back street MOT shop, cash only
well away from anywhere reputable!
They can't remove covers or trays to carry out the visual check, so DPS are pretty easy to get away with as they are hidden by undertrays.
But OPF are right there open and uncovered.