MtlClimb
The stock fender clears just fine and the fork arch is pre-drilled for mounting; I only have to get some SKS fork leg mounts to convert it, and I was too busy riding to go to the shop to pick them up yet.
I took the bike up to 70 km/h and there was no trace of vibration or speed wobble. I even tried inducing oscillation with a sharp tap to the handlebar and lofting the wheel over a bump at an angle at speed; not even a hint of resonance. Doing either of those would cause a serious speed wobble anywhere over 30 km/h with the Suntour.
I'm not sure whether speed wobble has been cured because of the new wheel, the improved fork stiffness, the extra travel, the superior damping control, or the slightly-slacker head angle, but whatever combination of factors it is, I no longer feel the need for a steering damper as the problem seems to be fundamentally fixed.
The full 120 mm of travel suits this fast, stable chassis just fine, too! Plus the pedal clearance is a bit better. Even though it's super-easy to dial the fork into a lower travel setting by simply attaching a shock pump to open the equalizing valve, I haven't even been tempted to try it. I love the plush feeling of the full travel, and when you set it up right with 30-40 mm of sag, there's not even much difference in ride height. I can charge right over the 50-mm-deep drainage V-channel on my street at full speed without even feeling a bump, while doing the same thing with the Suntour would harshly jar the front end; it's great to have a fork that you can actually adjust and set up properly!
The RST Spex 20-15 Air also seems like a really good option, as its straight 1-1/8" steerer doesn't require changing the lower headset, it can use the stock 100x15 hub, and it has integrated mounting tabs for the fender. You would only need a 1-mm-thick shim for the steering clamp to make its 30 mm stanchions work on the Load. 100 mm of air travel with adjustable compression and rebound damping would be a massive upgrade from the Suntour.