Hving sailed my Papaya III with the 507 Una rig with some sucess. The CE was in the right place (pretty much) i.e the same as for the plan rig. We diid have some issue with the sail swinging about a lot in the unsteady (in speed and direction)win. This is probably in part due to the fact that the Original Papaya has itsr CE 3cm aft of the mast pivot and the UNA rig only 1 cn aft of the mast(pivot). This is great for servo load but means minor gusts can give it a swing untill it settles again. So the question is? The question is whether it is a “good” idea. Would its benefit of direcly setting sails and holding them in position against the transient swing in a gust outweigh the possibly slower responce going about?.
In the hour or so we considered the issue the actual mechaics of a direct drive (not direct on the servo as shown in some threads) we consider neither difficult, or heavy at this size.