Pete,
Thanks for the perspective.
Partly defoliating early in fall for the purpose of hastening fruit ripening would seem to be no problem for fig plants grown in pots since I typically protect those plants from cold in an attached garage and prune the limbs over winter anyway, thus any depletion to the root area that may be caused by purposeful defoliation to hasten ripening should be offset either by the winter pruning of the top or by allowing for some recovery time in spring. So, partial defoliation may limit my future crop size, but at least I will have a crop. Defoliation may be the only way to get that crop some years.
As far as partly defoliating in ground figs, there may be no loss to the roots of significance, or at least that I care about. For instance, I defoliated the Mount Etna Unknown by only about a third or so and mainly only on the limbs with fruit. And some of those limbs (trunks) I am also ground layering. So, I will be taking those ground-layered roots (and limbs) away from winter and into attached garage where they can recover if not in winter at least in the next warm spring. The roots that remain in ground have the remaining leaves and trunks continuing to feed them.
Additionally, this Mount Etna Unknown was still growing new limb and leaves, limb wood that would be lost to winter freeze, so by party defoliating it, I am preventing it from wasting energy at this late date on putting on new limb growth that it will only lose soon anyway, either to winter, or to my pruning, or both.
And that goes for all my in-ground fig bushes. Until I might learn otherwise, I prune nearly all of them to the ground each fall, because they will die back to the ground anyway. Thus, they have a far more massive root structure than trunk (minimal, below ground or mulch) and limb (none). Consequently, they should and seem to grow back well in spring. Would they grow back stronger in spring if I did no late season defoliation to divert energy to fruit ripening. Probably. But if I don't get ripe fruit, there is no point in any grow back at all. They might as well die entirely and make room for more robust cultivars that can handle such treatment or otherwise ripen fruit.
The Binello will be an interesting test case because I defoliated it almost entirely, because it is one of my most exposed bushes, and because it is bearing such a heavy crop for its size this year. Given all this, I expect the bush to survive below ground this winter but would not be surprised if it cannot bear any crop or as heavy of a crop next year. I would also not be surprised if it then bounced back the following year to once again bear fruit. In that case, such bushes might need to be alternate bearing.
The other three main possibilities I suppose are 1) it could die entirely this winter, or 2) it could bounce back strongly and bear fruit as well or better next year as this year, or 3) the at this point unknowable possibility that next year, as an extra year older bush, the Binello might have handled defoliation in a way that it was not ready to this year as a 1 year old bush. We will see about the dying or bouncing back and be left to guess about the age question.
I also took a ground layer off of the Binello a couple weeks ago which I've potted up and which will spend the winter in the garage ready to be used as replacement if need be. Taking that ground layer might or might not be a significant issue for this specimen too.
I am punishing (by pushing) the Binello to get a crop this year, no question. We'll see if it can take it and to what if any degree in the future. Simply allowing this Binello to carry a crop as a mere 1 year old plant is no small strain itself, especially since it is destined to die back to the ground (or be cut back) due to the brunt of the oncoming winter. This year's unripe crop alone has severely limited the size of the "bush" (small plant really). But the crop appears to be coming in. Not bad for a few dollars worth of a cutting.
I did call this Binello "robust". Hopefully it continues to bear out. If not, I'll trying something else.