While the scramble to design for L-Brackets is on, I need one now. I have ordered one from RSS (which I may return), but in the meantime this one is working pretty well.
https://www.bhphotovideo.com/c/product/1056517-REG/promediagear_plx3_universal_l_bracket_3.htmlI include a couple of quick snapshots. Note that the L-Bracket fits because the ¼-20 screw can move at right angles to the length of the bracket a certain amount. See the letter “A” which shows you the screw. Note that one of the two stainless steel rods bumps into it. Now, this is OK with me because I want to leave room for the remote (which is plugged in in the images) and extends quite a ways. However, if you want the vertical part of the bracket to fit snug, you would have to use a hacksaw to trim the rod I marked so it does not butt into the screw. I still may do that, but right now all is just fine. The L-Bracket is strong enough and I have the FTZ adapter installed.
However, if I want to use really heavy lenses (Otus 28mm APO) I may want to use the tripod foot of the FTZ adapter for added strength. I have a second (different brand) small L-Bracket that mounts on the tripod foot of the FTZ adapter, and they fit nicely side-by-side, yet there is no room between the two L-Brackets to mount either one an Arca-Swiss quick release clamp. Bummer.
This means that on the occasions I use heavy lenses, I will have to take off the L-Bracket from the Z7 and install the other L-Bracket on the FTZ foot. I don’t like it, but at least it is workable.
A lot of my work is done in portrait (vertical mode), so I need to be able to work back and forth quickly. I know... there are other methods and some were presented here.
This is just what I am using for the moment, for those interested.