And the simple solution for most a/c that are too fast to land with the engine at idle is to put a prop on that engine with less pitch. That works great no matter what the power loading.

Most times, you'll never even notice a change in the top speed.

I've got a couple of .40 size models with powerful .46s on them. First thing I did was swap out the 6 inch pitch props that were the recommended ones, and bolt on 5 inch pitch. Granted, for one a/c, I had to cut down a 12x5 to keep enough blade to keep the engine warm enough, but the a/c lands at a fast walk now. Having more fan area is one of the best air brakes available, but only works if the pitch is low enough.