I have some autoflowers (almost) at harvest time. Need advise on partial harvesting

You could also reduce your lighting by one hour to get the plant to hurry up and finish. This is a good trick when you have plants that keep pushing out new white pistils and seem to be dragging on with maturing/finishing. Hope this helps, Organoman.

To clarfiy, it's not foxtails or any other irregular behavior. The entire main cola is still fattening up and showing white pistils up to the midgrowth. The water consumption has lowered a wee bit but is still significant indicating new growth as well. The problem I have is that specifically the side stalks and lower third of the plant have been showing signs of ripening for weeks now. Specifically all brown pistils and yellowing leaves. I've never had this before and can only assume it's because of the fact that I gave them much more room to grow this time around. Hence, should I harvest the parts that have been showing signs of ripening for a while now, or do I hold off until the main cola is ready to avoid causing stress....etc? Because that's gonna take another week for sure :)

Harvest whole plant sounds like your fox tailing and late in harvest window