I am not aware of any negative impact on tourism arising from the implementation of the Official Languages Act. Indeed, the implementation of the Act appears to have generated a vast amount of free publicity for An Daingean in particular.
As far as travel is concerned, the important thing is that the maps and guides fall into line with the official place names and signs as would be normal in other countries. I understand that this will happen. As the Deputy is well aware, tourism and marketing interests are, of course, free to use any names, including the English version of a placename, as marketing tools.