Don't have a clue about the newest T4-5 compliant tracrors, if the employ crankcase blowby consumption (back into the intake stream) or not. Do they? I don't know. I know that automotive related engines do (aka: EGR) but tractors, I have no idea about. Even my old 1997 7.3 diesel had it, but I removed it and added a 'road draft tube'. The only reason I did that was because When Navistar built the engine, they introduced the blowby vapor in front of the turbocharger intake stream and the introduction of blowby vapor in front of the turbo can and will cause the impeller wheel in the turbo to carbon up. Eliminating that vapor eliminates the potential carbon issue, consequently, I now have a road draft tube. Was easy to do as the engine has the vapor seperator on the drivers side valve cover so adding the appropriate venting was very easy and straightforward.
Always been my philosophy that the 'less junk in the trunk' equals less junk in the combustion chamber.