I too don't know how long XAXA will continue. But it has been the longest serving aircraft in the entire fleet, surviving from the Le Cocq's Airlink years to today. It might well continue - Trislanders LCOC and BEDP are both for sale. But no-one wants them as they're rubbish.
Aurigny have put extra blades on their Trislanders in an attempt to reduce noise. It didn't make much difference - just reduced the pitch making a lower sound. The rear engine was left out because it makes little difference to pax comfort anyway.