Switching from Atkins to SBD.... so in Atkins recipes that call for heavy cream... and I'd need to use FF 1/2 & 1/2... is the ratio the same, as in equal parts? TIA

Depends on the recipe. Some of us use condensed skim milk in recipes calling for cream.
Hey, welcome to The Beach!

I can't find a FF H&H that doesn't have sugar (usually corn syrup) in it.