If you are 5ft 7, you will require more than 2 inches of limb lengthening if you undergo 2 surgeries. Being 5ft 9 falls short of reaching the maximum height benefits; it may be more advantageous to aim for at least 5ft 11 after undergoing 2 surgeries.
I am precisely 169cm tall, and my sitting height is 83cm, so no need to fret. As long as your wingspan remains within 3 inches of difference, you will appear fine. This community frequently includes individuals with a natural wingspan difference of 4-5cm, equivalent to 1.75-2 inches. People with up to a 4-inch difference do exist, although I do not recommend it.
Although I have not seen you in person, I have simulated 7cm extensions to myself, and it appears satisfactory. I will not sugarcoat it; your proportions will not be perfect anymore, but you will not resemble a t-rex.
PS: Some individuals have short arms but broad shoulders, which broadens the wingspan but looks less appealing after limb lengthening, while others have narrow shoulders but long arms, which is the opposite).
