Yeah, I don't really do much more than that too.
I might soften the rear springs and maybe have a play with the diff if the rear likes stepping out, plus a couple of clicks on the front camber to get a bit more turn in, but I don't really know what the hell I'm doing.
I just drive the car, see what I think it lacks. Is it understeery/oversteery? Is the gearing obviously not suited to the track, or being a spinning sod when shifting to 2nd or something?
I then read the descriptions and see if anything good happens with the basic stuff mentioned above. All the advanced stuff like most of the suspension settings are beyond me.
The 643 time was done with just aero changes for example (17/22). It could have probably been lowered plenty more.
Conversely, I raised the rear wing on the 3-Eleven, as I found that Oulton favoured corner entry/exit and holding speed through fast bends more than it did straight line speed in that car.