Spoken “artificial” languages: are these still foremost in the minds of any significant number of people?
17. As for the use of “artificial” languages, proposed from time to time, the approval of texts as well as the granting of permission for their use in liturgical celebrations is strictly reserved to the Holy See. This faculty will be granted only for particular circumstances and for the pastoral good of the faithful, after consultation with the Bishops principally involved.[Cf., for example, Congr. for Divine Worship and the Discipline of the Sacraments, Normae de celebranda Missa in «esperanto», 20 March 1990: Notitiae 26 (1990) 693-694.]
The only problem I see with this paragraph would be handling modern manufactured languages like what the deaf and hearing impaired use in various countries.
Catholic Sensibility 
I’d argue that the language in the new Mass we are all to participate in starting in November is such an “artificial language”
Regarding your last concern about “manufactured languages” for the disabled, aren’t systems like ASL and BSL already based on English?
And propos of nothing, there apparently is a translation of the RM in Esperanto from 1995.
You mean no mass in Klingon?