It is interesting to hear the various theories -
Here is yet another .
On the airfoil used on the fullsize Sukhoi and CAP /EXTRA, Note that it has a large BLUNT LE and then a straight line to the truncated TE.
One theory/guess is that the truncated TE adds a low pressure region, which actually assists in holding the airflow laminar to the flat wing surface-- remember -this is not the old shoe curve airfoil .
Onmodels -- for my money - make the aileron as stiff and light as possible - the rest of it matters very little.
I don't use sealed hinge lines etc. but I am a bug about keeping the cg of the aileron as forward as possible.
On my lil foamies - -these are just flat foam - hinged with surgical paper tape top and bottom - -but the speed is so low - an the weight is so low - it works very well -
When we did pattern designs - we never used thin TE on ailerons - just a waste of time and they got flimsy