I’m no guru, but find this fascinating, and am reading up on all the details as you are.
Probably the most important thing to remember (occurring only recently for me) regarding wing design in planes is that they 1.have ailerons which need lift to function, 2. cost limits construction. So you will see designs that prioritise root stalls first to avoid the airflow at the ailerons stalling, and the boxy shapes are easier to construct.
I think for user friendliness you want the gradual stall. Here is a nice clip that walks through the progressive stages of a gradual stall, this is to avoid a tip-stall at all costs, as that means instant loss of roll control (in a plane, same doesn’t apply to a foil with no ailerons).
Both ailerons and construction constraints are largely irrelevant to our foil design. But the trade-off is still there, in our case performance vs stall characteristic. Outright performance the elliptic shape and variants is optimal, but a boxy shape will seemingly have a more progressive stall rather than an abrupt stall. Based on this article
For performance, my understanding, an elliptical shape makes the most sense, with some interesting reading around spanwise flow, crescent elliptical, and the rc crew discussing the varying benefits. Seemingly the most high performance tails are all tending towards varyingly elliptical for the top of the range (KDFoil, Axis). Interestingly, F-one has a tail with fences, a different approach.
Below shows the efficiency of the spitfire shape, discussed in the RC Group:
Commonly applied is washout, where the AoA is reduced at the tip, and profile is more symmetrical,eg the ART range. I’ve got no idea if this is applied to tails, but it makes a lot of sense for main wings, eg below with reduction in AoA and slimmer profile towards the tip
I don’t really understand the design considerations for a tail entirely, as the characteristics are removed from plane design, and so this relies on some expertise and experience to get right 
lower takeoff speed for the same area, incredible pop, ventilation recovery, and smooth riding through turbulence in surf R Series Tails – KDFOILS
Clearly it make a huge difference, and KDfoils seems to get it right and people seem to agree