You can irimi and still be in front of uke and you don't have to diffuse the attack. I was teaching this today at my dojos private lesson time slot.
Without seeing what you are teaching it is difficult for me to ascertain what you were doing in your private class.
Since irimi is entering into an opponents attack [avoiding direct contact ] and usually done with the objective of entering the opponents 'blind spot ' or behind the guy I fail to see how you remain facing your partner.You may be at side/rear of partner but not in front.Why irimi if the resulting irimi movement from you means you are relatively speaking in the same position as before?
As far as your statement that you dont have to diffuse the attack of you partner this runs contrary to Aikido principles.Aikido seeks to neutralise the attack whether by tenkan /irimi then controlling the situation.If you do not diffuse/redirect the attackers energy you have to be physically more powerful than your partner.By neutralising partners power , you can initiate a waza with relatively little effort on your part.