With or without Home Rule, what would the effects be. Well Dublin* and Cork get bombed in WWII, heavily. The Irish ports are quite useful to the war effort. Ireland is not isolated for a generation after the War. Anglo-US relations still have Ireland as a sticking point. Irish Parliamentry seats could play a role if the OTL elections of 1964 ans 1974 go the same.
* Yes I know Dublin was bombed OTL, it was a "mistake"