Interesting topic.
I thought JAR/FAR 25 acft had to calculate the eng failure climb gradient before each takeoff. So why not follow a SID if the acft meets the procedure. Where I come from we have a lot of SID's with gradients well above 3.3%, but what is the typical gradient for a acft with one engine out (i.e B737,A320 etc)?
For the record. I don't fly transport cat. acft yet!