I'm not sure CBG is the place to have an aircraft go tech, it depends on the aircraft. While Marshalls (who own and operate the airport) are a fully-fledged aircraft maintenance company, they may not have any engineers qualified for a particular type.

This was a serious issue when Darwin Airline (now Etihad Regional) operated CBG-AMS and CBG-DUB - despite all the facilities available, there was no Saab 2000 certified engineer available so if the aircraft went tech (as it did far too often after waiting there overnight) the early morning services were doomed. After a while Darwin stationed an engineer there to handle issues and the dispatch reliability improved significantly.

So unless Sun Air have ensured there is a Dornier 328 engineer there, Marshalls will not avail you.