At 2 1/2 yr old it would calm it right down to the minimum but i suspect he would still spray just from memory and habit
I agree in that as he was stud boy he will be used to sleeping outdoors and as a "sprayer" it's what he knows if you don't neuter him he may develop other issues from pure frustration and of course your girls will answer his spray with theirs and so on..also it won't do your homes aroma and furniture any favors
Did you get him as an active stud or as a retired stud??