It appears a neat little outboard.  If it is durable it will be good value.

The T of L-foils can be raked to alter the AoA.  Canting the T-foil shifts the angle of the force produced.

The error I made with my L-foils is that I have cambered the vertical portion.  That means at level flight, with both foils immersed, there is drag associated with forces that are doing nothing other than opposing each other.  The camber will be beneficial when sailing if the ww foil is raised so the camber on the lee side prevents leeway or I allow enough roll to lift the ww foil almost out of water.  The problem with that is the canted sail has  downward component. 

To counter the heeling moment, the line of the force generated by the foil should pass above the CoE.  That usually means you want to get the foil as far out as you can.  

If the boat has negative heel then that is good because it cants the sail to weather and that means the sail is providing a lifting component.  Although the lee helm increases.

With the T-foil you should ideally aim to have the rake and cant settable so you can maximise VMG.  It needs to be strong because, at the limit, it could be supporting close to the entire boat weight.    I expect that my L-foil will fail if I push above 15kts.  It is easier to make a T-foil with high load capacity.  

I expect the top of your T would be 100 chord x 600 span for reasonable efficiency.  The middle of the T should be long enough to get the top of the T at least 100 below water level.  Assessing CoE at 3m above the gunwale of the stabiliser, which is 1.7m from the centreline, the cant angle would be 46 degrees off vertical to put the line of foil force in line with the CoE.  

The most efficient foil is one that prevents leeway as that minimises hull drag.  That is best achieved with a cambered foil.  I aim for a 10% thick, 16 series section with design Cl of 0.8.  That gives almost flat on one side so is easy to make.  You can alter the AoA to maximise VMG.  Once set it will be close to ideal for any windspeed on that point of sail.  It will produce negative leeway and extra drag when reaching further off the wind.  Alternatively you might set it for maximum reaching speed and tolerate leeway when aiming for best VMG.  The central portion of the T will not require much leeway to generate extra lateral force but that comes with a positive heeling moment.  On such a short waterline you may find it is better to sail faster further off the wind  to reduce pitching.  

The described foil at AR of 6 will have a Cl of 0.8 at 2 degrees AoA with L/D of 18.  At 10kts it produces a force of 600N.  At 16kts the force increases to 1350N.  If you were game to take it to 20kts the foil would produce 2400N.  Vertical component at 20kts would be 1680N so the weight of the boat plus a portion of the pilot weight is supported by the foil.  That 1680N lift comes at a cost of only 133N.  This is a fraction of the drag that the stabiliser would have when carrying that load.

The cant angle should be set to eliminate heeling - per my estimate above, around 45 degrees.   

A canting T-foil would make a huge difference to the boat performance.  It has short hulls so they will bog down when pressed if not being unloaded by an efficient foil.  It will be harder to tack with foils down but the pedal drive will help with that and you should have the facility to easily raise the foils from the cockpit.  I have that as an idea but not yet implemented.

Rick

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