If one put two crafting cards into a crafting manager with the same output, just the first crafting card works and the second one is ignored. This makes an alternative recipe impossible. Altough, there is a work-around: using two crafting managers.
It would be nice if the use of alternative recipes worked with only one crafting manager, esspacialy if there were more than two alternative recipes.

This also happens if you use a chassi pipe. This is a bug in Logistics Pipes.