I have 40mm nanos on mine, there isn’t a lot of room to spare. It wouldn’t take much of a wobble for the tyre to rub.
It has transformed the bike though, (along with upgraded bars and stem)far more capable off road.
The tyres are good but do struggle a bit on slightly moist chalk, I think they might get a bit of a handful in wet conditions and will probably go for something narrower and grippier.