Okay here is my 2 bob's worth,
I think it is a "GREAT IDEA IN FACT BRILLIANT"
In simple terms if you double the pressure you get close to doubling the amount of O2 for the same amount of rev's on the SC. I have a GM diesal generator that is 600hp and it runs turbo to Intercooler and then to a SC. The main reason they do this is the efficency of the engine is greater by having double boast then single.
Slightly off topic but we have 3 by 1,000 hp electric refrigation compressors and by using dual stage we get greater effecency per Hp input.
In simple terms any compressor on gas (O2) becomes less effecient the greater the amount of boast. The brillance of your idea is it enables you to control most of the heat but also get the benfits of the SC.
Tony