Any way to make the steering quicker?

The problem with making the steering faster is that it would work against you when you go off road. By that I mean it would tend to spin the steering wheel a lot harder when a tyre catches on a rock or stump or whatever and it would also magnify the torque back into the steering wheel too. This would make it very easy to snap your thumb off when you forget and leave it inside the rim of the steering wheel. That's assuming it doesn't snap your arm. As I remember you have said you are or intended to go rally raiding in your jimny so off road at speed is only going to make the kickback worse. The steering is slow for a good reason.

Fake it with a smaller steering wheel

You're not wrong now that I think about it, I might just get a smaller steering wheel and limit myself to that

Get a smaller wheel and fit a "spinner knob" to it like on a forklift (or a traction engine...)
Probably illegal to use it on the road though, unless you are disabled.