This raises an important question if I understand you correctly.
The Church teaches that the marital union has both procreative and unitive significance and each of these is important. The Church teaches that these should not be separated. But it seems to me that of the two, the procreative aspect is given much more significance. I say this for two reasons.
The first is one of the points that I think you are getting at. The unitive aspect is given some value, but its value alone does not ‘justify’ the marital act. For example, some women, particularly those who are avoiding pregnancy for medical reasons, feel such anxiety about NFP that the act cannot really be said to be unitive for them. Some have suggested they could limit sex to infertile periods and still use condoms, arguing that the diminuation in the procreative aspect is justified by the increase in the unitive. Current Church teaching seems to preclude this. In other words, even a small amount of procreative significance trumps even a large change in the unitive significance.
The second point is that although we often say that the unitive and procreative must be present in every act, that is not really what the Church teaches. HV says every marital act must be open to procreation, but does not actually require that every marital act be unitive. The Church encourages couples to take each other’s personal and emotional conditions into account, but many Catholics would say that a spouse has the right to the ‘marital debt’ whether paying that ‘debt’ has a unitive or a divisive effect.
In fact, despite all the crowing about how in HV the Church recognized that sex was more than procreative, and that sex plays an important role in marriage, the reality is that the unitive aspect, while recognized, plays no practical role in deciding the morality of sexuality. The Church’s teachings are framed differently, but the bottom line remains the same. It would not be inaccurate to restate HV like this: Sex is a morally charged act that must be justified to be moral, and sex is only justifed if it is ordered towards procreation.
This seems inconsistent with the implications of Deus Caritas Est, and with some of the other things Benedict XVI has said. This is why I commented earlier that I would not be surprised if something would said on the topic during this Papacy. If he wants to adjust this teaching, Benedict XVI has the stature as a theologian, and frankly as a social conservative, to do so. But I may be badly misreading him.