I don’t think the dark period before chopping it down is that extremely important, at least not for that long anyway.
As @latewood likes to remind us, the plant is not dead even after being chopped down, and much of the biological activity will continue while the plant is hanging in the dark, very slowly drying, kind of the pre-cure early dry part of the entire process.
Also, I think the solid 12 hour dark period on the last day of the grow cycle is mostly good enough, and if you time it in such a fashion that you give the plant an extra 12 hours darkness tacked onto that last night, so you have one 24 hour period of darkness for the plant before harvesting, and then a following approximate 12 hours of darkness, more or less to fit a schedule for when it is convenient for you to chop it all down at one sitting, then you have almost 36 hours of complete darkness, and from what I’ve read up on the subject, this amount of darkness, 36 hours, is what seems to show the most benefit, and any increase in dark period beyond this for most strains has not been documented to show any significant increase in yeild, weight, density, or potency.
Also, here are some other thoughts on this. Some studies do show resin production seems to peak right before the light would come back on, or the dawn outdoors. Most growers that practice this do seem to agree more than 48 hours does not show any real benefit for the mass majority of strains they’ve tried it with, a few exceptions not withstanding. That last 36 hour dark period would put you at the morning of the second day if you get my meaning, chopping down right after that 2nd peak resin production. And I really don’t think the plant is going to do much more than that after that, as actively biologically it really doesn’t do much at all during the dark period, above ground anyway, and any longer and you are starting to ask for problems, maybe inviting rot and such.