Thanx for taking time to explain further. Much appreciated
So it is not in fact irimi, but a 'tight' form of tenkan. We practise a form where tori 'takes' the center and deflects the bokken of aite. Tori in this case does not (should not) move away from the center line.
The training material was meant for bokken being practise instrument of the shinken and basically there is no difference in handling them.
Bokken is simply safer in practise, especially when 'searching'/'exploring'.