One reason I haven't had the engine start during EV mode is because my battery is cooler when I stop to charge it. I think you get problems with the engine starting after the battery exceeds 113F, but maybe someone here can confirm that now that we have a battery temperature x-gauge.
I've had 3 engine starts on non-empty batteries since I got the ScanGauge. One at BaT of 113 F, one at 114 F, and one at 111 F. The 111 F one was ramping up very fast, so maybe that's a criterion as well.
I prefer to drive with the windows down and the A/C off, so my interior temperature is mid 80s. I'll try running with A/C and see what that does.
I don't know where the temperature sensors are for the climate control or the interior temperature reported by the ScanGauge. My guess would be the climate control is somewhere near the driver's seat and the OBD report is near the battery air intake. The ScanGauge temperature initially seems much warmer than it feels to me. The air around me soon gets to a comfortable temperature and the A/C drops to a low power, but the ScanGauge interior temperature keeps gradually ramping down towards the climate setting.