Adding to my crypic but not very useful jibe above (Pioneer space capsule image for aliens to take a gander at) which went much further than a scissor kick or dolphin kick that most of us have figured out long, long before we got our own hydrofoils.
More wing area, width especially adds to stability when standing up as does speed and good solid, rigid connections between all the parts.
More wing area is also a partial compensation for poor floation, i.e. if you start with a board only slightly more than your weight but you get a super wide wing then as soon as you start moving your stability will rocket up. But less than your body weight and you will need a lot of failures and dogged persistance + some unusual talent to still progress.
Screws alone won't hold a low speed hydrofoil together, you need sockets or wide areas to distribute the side load from the wing tips over a greater connection area and to reduce the shear loading on bolts.
Be well researched in your first foil purchase. More foil area is easier to learn on than less. You will want the biggest range of compatible wings with the kit you buy if you are expecting to get more than one size in the future, beware of end of life fuselage design versions that you might not be able to buy wings for in 2021, 2022 etc. I'd like and am promoting standisation but it's a way off yet!
Watch the wings you are considering buying on video first. Pay special attention to pumping efficiency getting on foil and handling when trailing the wing down wind. Some are horrors and need special techniques to avoid wild penduluming.
Inflateable boards can be plenty rigid enough but won't release and plane as well as hard boards. In the air it will make very little difference excepting that a hard board can have a scooped out deck to fractionally lower your centre of gravity. Wedges to convert curves to hard planing edges can be easily made to stick to inflateable boards to improve planing performance: -> https://pinshape.com/items/103157-3d-pr ... ng-wedgies
Wing window material may not be cold weather friendly. If you buy a wing with windows then unless you know it folds easily even in cold weather then roll the wing instead and don't fold over the window area. People in the tropics... I'm envious!
I've seen it in lots of tutorials and I'm only a newbie myself but I'm going to repeat it: Unless you are already a proficient foiler then start your learning in slightly stronger winds for your weight and wing size than proficent people need, concentrate on only just lifting the board so that it is just kissing wave tips. This will let you more easily develop the muscle memory to control the twisting and rolling motions you need when you are higher up, but with less wing perforations and dolphin breaches of the foil.
Where to learn: You need deeper water than the mast+fuselage + wing + board displacement with your weight.
While learning you will be doing a lot of down wind. It's not bad, it's part of learning but if you can take your gear up wind and do a long down wind then great. Wind against tide is also good.
Weight over C.O.G. and arms holding wing as far back as possible helps to go upwind when you are schlogging(not up on the foil)
Learning in a non wavy area is a utopia, if you can find it I'm jealous!
Kiters, Wind surfers: You don't need massive pull on the wind-wing once you are up on the foil. You also don't need to heel the board and foil way over like a kite board, because the foil is very low friction at it's design speed range, you only need a few KG pull on the wing so for you kiters and wind surfers, as soon as you are up on foil, DON'T keep hanging on to the wing for dear life, relax your back hand and concentrate on your stance, on a controlled turn more up wind to increase your apparent wind while NOT stalling the wing. Concentrate on keeping the foil flatter and just shift your C.O.G. slightly to ballance your turns and the pull of the wing.
Schlogging upwind: The "V" of the wind wing and it's inflateable centre strut act like a giant rudder, point the wing slightly across the wind in the direction you want to go and even when held almost horizaontally, it will pull you the way you pointed it just from that twist in the horizontal plane, you don't need it on it's side to steer. Move your weight as far back on the board as you can while still being stable and move your hands as far behind you as you can and you will point up wind in no time, find the happy medium where you are moving slowly up wind and watch out for gusts to plan your moment to point more across/down wind and pump onto foil.
Very wide light wind windsurfing boards are a definite option for learning to hydrofoil on. You can likely pick them up for less than a purpose designed learner foil board but beware that the foil connection area won't be as strong, they will likely need reinforcement, i.e. a couple of 150mm wide 200gsm strips top and bottom of deep tuttle box for a length of 300mm would possibly be the difference between breaking or not breaking on a good impact.