I use the Neewer CA134 L-Shape Grip for Nikon Zf ever since it came out. I usually keep my voigtlander lenses on the Zf and i have on occasion mounted both the 24-70 and 70-200 on it. Yes it's heavy but i have no problems with it.
I don't use the camera without the grip even with M mount lenses which I have recently acquired.
I bought Neewer CA134 grip, and i don't like it...thumb rest is great, but front grip is too small...I bought Smallrig 4801 Wooden grip...and it works fine for me...it's bigger, but it don't have thumb rest, but i get used to it.