lederhosen, a smaller stabilizer will not increase, but decrease the front foot pressure, as the stab lifts a tad downwards in straight "flight", so a smaller stab will feel like it pushes "up" (less down) on your rear foot.
It is IMO not really noticeable, very little, but using a stab say half the size only, you will need to stand an inch or more furher back yes.
Can be compared to removing the stab fully, then you need to step back on the board.
jumptheshark, a good question, I have two thoughts, and knowledge/experience from aviation:
For gliders, as long a fuselage as possible is used.
This will let you have the rudder and elevator in more free non turbulent wind, and also use smaller control surfaces with less drag.
Last but not least, you get a more responsive rudder, if used for competition soaring fast turns.
Then the opposite also exists, namely that really short fuselages with big elevator can give you a super narrow "loop" radius, so for aerobatics this can be extremely fun.
For a hydrofoil, we dont use the control surface(s) the same way, as we steer by weightshift and yaw input instead, so the agility gain from a short fuselage and big stab would probably not exist the same way.
BUT, I think a superlong fuselage and small stab will at some point give you more drag, as the fuselage will not always stay in the waterstream, as you ride with different angle of attacks going upwind, versus going fast downwind or halfwind.
And the stab might stall in tight turns too, as the aoa gets pressed too high
In turns it is evident, the fuselage is turned quite extreme, and you can easily see this on photos from above if you got a bit of bubbles also.
The fuselage should be bent both horisontally and vertically to follow the flow.
So too long might not be performing better, at some point.
Apart from this, the practical issue, a long fuselage will increase the risk of hitting the bottom when starting in low winds, or you hitting the foil with your feet when in the water.
This is why I think there is a limit, where a longer fuselage becomes a downside both structurally but also in terms of aligning with the flow (curve) when carving, see the pic here that shows when you do a tight donut (360), the fuselage can not follow the "curve" and will be very draggy.
On this pic I get some air into the wing tips (happens often if you do a lean back 360 instead of the upright ones), but that is not my piont - it is simply that the picture shows how much curve you have in a tight turn or donut, and why a shorter fuselage, or no fuselage, would work well
Having said that, it is all down to how it feels, and nothing but that - and this is most likely the reason we got the current length of most fuselages, somer shorter like the early Spotz racefoils, and some longer, but still about the same range.
I just think the stab sizes are WAY too big for todays way of riding, thus this thread