I do not have my own 3D printer - but I was wondering whether it is possible to create an enclosure with lettering of a different colour to the main part. This would mean that the print job would have to automatically pause whilst the reel of plastic filiament were changed, also it means that the enclosure labeling would have to be a final, separate task. (Unless, that is, the 3D printer used had a way to automatically select different filaments.)
Thus the un-labeled enclosure would be printed first, then the filament reel changed and finally the lettering is applied - as a surface finish to the existing enclosure shell.
For example, an 'A' shaped groove could be laid down on the main enclosure. Then, in the 2nd pass, the 'A' is printed again "on top of" the "'A' groove" - in a contrasting colour, and with some given thickness.
Somehow, on the 2nd pass, the print job would need to be "aware of" the existing 3D surface so as to apply the 2nd colour at the correct point in 3-space.