I read somewhere once that if you add some cornflour to the evaporated milk before adding it to the dish, it will prevent it from curdling but can't vouch for it as I usually add the cornflour at the end of cooking, not beforehand. I often use low fat evaporated milk/coconut flavoured evaporated milk myself in dishes to reduce the fat content (instead of cream or high fat coconut cream/milk) and don't have too many disasters. Lower temperature for sure and of course the taste is not compromised when it does separates - it just doesn't look good, especially for visitors.
