If we are going back in time then it's important to mention that single power lever piston engine operation has been around since prior to WW2. The Germans had the Kommandogerat system fitted to the FW190 and a few others where all power was set through one lever, prop, mixture, throttle, timing and supercharger modes. The US had simple interconnects on some fighters, but not a true single lever operation. Not sure what the FW190 in Australia uses, I'd assume traditional controls as it's not using the original BMW 801.
In any case I think most trepidation over single power lever ops is more to do with FADEC rather than the older hydro-mechanical mechanisms. Depending on how much control the FADEC has is where the problems can lie, ie automatic engine shut down if it doesn't like it is something, I don't like. Automatic engine controls have been around for ages from a mechanical point of view, and are very reliable. As said above a CSU prop is a simple mechanical automatic speed limiter. And most fuel injected aircraft probably have some form of simple computer involved.