I have taken wobble out of rigs by adding a couple inches to the lead but that was on rigs where the lead was already on the short side, 4 or 5 inches. You are already over 9 so you are there.
Is the wobble only at low speeds? I assume that since you are in the testing stage you might not have had it up to speed yet? Many times rigs will have a low speed wobble but goes away above 10-15 mph.
You said you checked your steering bearings but have you tried overtightening them so they drag a bit?
When it comes down to it sometimes you just need to install a steering damper. I prefer to mount them from the front sidecar strut to the triple tree or a part of the fork that doesn't move up and down when the suspension cycles if possible. It is possible to mount them to the fork lower but I would try not to.
How are you measuring your toe-in? Are your mounts nice and solid without any play?
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