Clan Crafting Question

[Rydall]

When crafting an item from the large workshop it says that you need contributors (level 3 on a certain profession/craft). Does each contributor have to be online at the same time to start the process? or can I have them sign/contribute when they come online and start it once I have enough contributors?            

[Shuchin]

Not having tested it, I understood the explanations on livestream as if the latter was true: Anyone in clan can sign off those craft contributions, and once all is together you can initiate the craft?