partial carbonic maceration

I’m trying an experimental cuvée this year. Whole bunch Syrah and Carignan, co-fermented by starting off carbonic maceration and then finishing off with yeast, wild if it happens, innoculated if not.

Has anyone tried this method and how long would they recommend doing the carbonic before opening up the vat and getting the yeast working?

partial carbonic is what you get at the end of an open top fermentation utilizing whole clusters.