Good luck getting any response from the Evoscan guy, the website hasn't been updated in ages, the links for images and diagrams are mostly broken and on many Mitsubishi forums I've read folks are complaining that they sent their payment and got no response. Unfortunately I believe the software needs a serial number from him to activate unless someone has made a crack for it. It may also be tied to certain cables; maybe others here can chime in with their knowledge.

As a last resort, can the stepper motor be manually turned to a roughly midway position and refitted without plugging it in? If so you could adjust the screw for an idle speed which doesn't stall, let the engine warm up fully then adjust it again for a suitable idle, then plug the stepper back in. Would that work?