As teaser said, it depends on what you mean by IF. A 19/5 or OMAD, is merely "Time Restricted Eating" something most on low carb can do if they wish, and it is very flexible.** I might plan to only eat dinner, but then get invited to lunch, so I switch it up as fits my routine. Not eating a whole day, therefore doing a 36-42 or 48 hour fast is good for weight loss, but again is very flexible. I may plan to do that M-W-F but social life often intervenes, so consider those changes part of "keeping my body guessing" Longer than that gets into therapeutic uses, not the focus of this forum.
My view is that IF + LCHF makes the social and lifestyle aspects much easier. You become more aware of the When to Eat part of weight loss, avoiding the snacking and grazing that is part of life and even some weight loss programs (looking at you, WW and Slimfast )

**You mentioned going back to the Westman diet in WWGF. I still remember how surprised I was at the first support group attended that the women at my table had coffee for breakfast, a light snack early afternoon, and then a nice LC dinner. You could call that The Warrior Fasting diet, but really it is just TRE, what Dr Westman called it. I had been plodding along with three squares plus a snack, and finally what he said to me in the clinic...Eat when Hungry...worked.