So not impossible for them to fit in something like...
IoM - Glos - Jer - Alderney - Jer - Glos - IoM? It would just mean moving their return flights from Jersey back an hour or maybe less.
Or Add ACI in on the Glos - Jer route perhaps. But I am guessing their IoM - Jersey pax would be vexed by two stops in their journey.
I had a quick look at their site for June and they only look to be doing Saturdays. No bad thing at all from an Alderney perspective, though the article said the States of Alderney would like two week to bracket the weekend. Presumably they are thinking Fri afternoon and Sunday afternoon are ideal.