Your leak is something to do with the float valve or the float.
The factory float level acceptable range is from .90 to .98" .94 is right in the middle and allows for a little tuner error. If you use the same method to set all four, I doubt the leak is because of the level adjustment. And if the float operation appears smooth and the floats haven't been damaged, it's likely the float valve isn't sealing.
Only other thing I can mention regarding the floats is to look at the "bright spot" where the adjustable float tab contacts the float valve spring tip. Usually, the spot is just a little rub mark that's smooth. But sometimes the spot can wear enough (pit) to cause a new or replacement float valve to not seat correctly. The new float valve spring tip won't line up perfect like the old one and it can lead to a sealing problem. If pitted or you see/feel a slight bump or lip to the spot, just gently rub it out with emery cloth. Just rub any bump or lip smooth. Don't bother to rub out the whole spot.
If that's OK, I'd focus on the valve.
Did you buy new float valves? Are they aftermarket? These aftermarket valves are often made cheaply and I've had new ones leak upon the first leak test. I always suggest to the owner to buy genuine Mikuni valves but I know they're expensive. I just want you to know the cheaper valves don't always work. Also, if you're using used valves, they MUST stay with their valve seat. The seat and valve wear as a unit and leaks can occur if you mix the valves and seats up. Also, check the valve spring for good operation. Is there any slack in it? Hold it with the spring facing up. If you gently push it in 1/2 way (no more) and gently release it until it stops rising, can you still pull out a little more? If so, that's too much slack. Do the test by using your thumb nail upside down because if your skin is a little sticky, the spring pin may stick to you a little. Also, if used, check the valve tip for grooving. Too much grooving will cause a leak.
After all you say you've done, I have to believe it's the valve and/or the seat.
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