Check out Dan John's writings on the velocity diet- macros are roughly the same as the RFL, VD is just 95% shakes. He did very well at keeping his strength up. Personally the VD would bore me senseless.
I'd suggest (though you didn't ask) that you first try a straight Very Low Carb diet with less limitations. Sub 28 grams a day of (net) carbs, only from green veggies, more fat than the RFL and a LOT of protein. I was able to lose a ton of weight in my 30's this way after a long period of bulking w/o much strength loss. I think Alwyn Cosgrove calls this "green face"- you can eat any green veggies as much as you like, and anything that had a face. Works.