I bought an ML-L7 bluetooth remote and it does appear to work with the Zf, and seems to function reliably. However, there is a slight delay that does not exist (or is much shorter) in electrical triggering (e.g. using MC-30A on a Z8 or other compatible camera).
I noticed somewhat anomalous behavior in the ML-L7 with the Zf set to B or T mode, in both cases the function is the same and it takes one press of the remote to start the exposure and another press to end it. This is okay for me, but it isn't in the spirit of how B used to work. I don't see how B or T would be used without remote activation (either cabled, not supported by the Zf, or bluetooth) without causing blur. If you press and hold the shutter button on the camera in B mode, there will likely be significant blur. If you use the remote, it acts like T whether it is in T or B mode. If you press shutter button in the camera in T mode, there might be slight blur and when turning the knob out of T position to stop the exposure, there is likely to be additional blur, unless the exposure is very long. So there is no practical use for separate T and B settings on this camera IMO. You could just have T on the camera and all the useful application cases would be covered. If there had been a mechanical or electrical cable release option, then one could press and hold it to achieve useful function in B mode, and on camera the T mode would be useful for shots of several minutes (presumably then the slight blur would not matter).
I will now stop complaining about this issue for the time being and start collecting some experiences using the camera for taking pictures. ;-)
By the way the camera is quite heavy and I find it balances perfectly with my f/1.8 Z lenses. I find there to be reason to purchase separate compact or pancake primes just to make the camera feel comfortable with.
I can say that I love the fact that one can more precisely define the custom wide-area modes in finer steps than in previous cameras. And the VR in camera seems the nicest I've used.
Since I've seen some reports that one can get the Zf to display a temperature indicator in still photography, I will try to see where the limits are with the production camera. I will also try to see how the DJI RS 3 Mini operates with the Zf, and how the video quality compares to the Z8.
The Smallrig grip that came with the camera fits nicely but I find it makes the accessibility of the sub-command dial not as good as it is without the grip. It can still be used but the access to it from normal shooting position is a bit tricky. I think this will probably mean I won't be using that grip and I'll just use my usual L-brackets. Access to the battery and memory cards in not hindered by the grip, which is nice.