A long time ago, when snowmobiling was young, a few enterprising souls fooled around with converting the snowmobile engines of the day from piston-ported to reed-valve induction. Often by stealing parts from outboard engines. The costs were often outrageous; had to buy reed valve components, weld and machine engine cases or cylinders to accomodate , etc.
Peak power often suffered, but advantage was gained in flattening the power curve. Would that be an advantage in milling? Perhaps, but a sharp engine tuner could possibly lower your tranfer ports and "peak" your exhaust port to broaden your torque peak with less expense. Of course, you tailor your torque peak with the tuner, as well, but a tuner actually "supercharges" the cylinder right around a certain RPM, with some consideration for atmospheric conditions, but can actually rob power at other points.
Do you need to know exhaust temps to try to guage whether or not a laminated carbon-fiber exhaust tuner will hold up, or are you working out tuner dimensions based on gas densities, etc?
There used to be a book, now out of print dealing with many of these issues:
TWO-STROKE TUNER'S HANDBOOK ISBN 0-912656-41-7 (an out of print classic) Gordon Jennings, H.P. Books.
If you can find a copy, it's a gold mine.