Living with long last names: a poll among the readers

I have recently posted about a new law which allows French mums to transmit their last names too to their progeny. I have been thinking about adding my last name to Milo, and consequently to his coming brother. As the deadline for presenting the papers approaches (June 30), discussions have intensified with the Belgianite, who declares himself in agreement with the principle but is very skeptical on the fact that we both happen to bear pretty long last names, and is convinced we are condemning our kids to a series of impracticalities which will make they bureaucratic life a nightmare.

I can’t make my mind up: am I being too selfish? The main reason to add my last name is to give my children the option to pass it on the day they will have children, especially if they will choose to live in Italy. It is not about a narcissistic need to see my last name associated to their names daily: I’d be happy with them using the father’s last name in everyday life, however, a city hall officer confirmed that they will have to use both last names in every official documentation (from school registration to the bank, and so on).
The Belgianite flashed me a credit card, a social security card, a passport and said: “Look! There isn’t even enough space for our two last names!” (which, together, account for 20 letters). I suspect that his cold and rational approach do hid an emotional reason, somewhere in his unconscious…
Objectively, I think we are not going to be the only ones in this situation and the administrations will have to adapt their forms accordingly, if they haven’t already; also, as previously noted, in France the double last name is a custom already present among the old aristocracy, so we are certainly not the first ones with long and complex names; finally, technology is constantly evolving, by the time my boys will be 18 they won’t probably circulate with passports and ID cards anymore but all our data will be retrieved by the iris of our eye or a chip in-planted in our index, or via fingerprints.
The only painful view from the future that such a decision brings me is when I imagine the kids in elementary school, learning how to write their names and spending hours to spell out their full last names…
So, I ask my readers to manifest themselves with their opinion, especially the ones who have a long last name, those to happen to have a double one or know someone who do, and let me know if it has been really an handicap for them or not and to what extent it has been a pain in the neck (if anything) in their lives! Help me make the right choice!!!