Actually a mod in the mini is really fun, the issue is getting the power to the ground.
There is a company in Japan that makes a different gearset for the mini, but it is not TCS legal.
The only comment about David Beales article is, there is a new style U joint out for the mini, other than the one he listed, and I feel it is a better part.
Also on the Tamiya track I have run a much harder spring. Also if he didn't mention it thay also offer a swaybar kit, and I find I use one end or the other to tune the car.