At this point, your supply is pretty much regulated and it wouldn’t dip too much. I would say go for it for a week and see how it goes.
I do IF sometimes 3 x a week and I’m currently breastfeeding my 11 month old. It doesn’t seem to affect my supply- but I’m also planning to wean at 12 months
My son is 4 months old and I have been back doing IF from about 3 months post partum. Have noticed no issue with my milk supply - maybe after doing IF for years I find I naturally stick to a 16:8ish window without realising.
Anyway, no issues with supply!
I’m tandem feeding a nearly 3yo and 16mo. Can do anything from 16:8 to 20:4 with no issue. On top of that I’m away from them 12 hours at a time a few times a fortnight without pumping and still have no issues. I just eat to satiety when I am feasting, drink enough water and electrolytes. I don’t think you’ll have any trouble with 16:8 but you could always start at 12:12 and move to 14:10 once you’re comfortable and so on. Good luck