Not an iPhone ... but yes, with an iPad Pro 10.5 (lightning connector) and the Apple "Lightning to USB3 Camera Connection Kit".
I'm using a 20,000mah powerbank with USB-A and USB-C outputs .... run a cable from the powerbank (USB-A - Lightning / USB-C - Lightning) to the power jack on the USB3 Camera connection dongle. Power up the powerbank, then connect the BFProFS USB cable (supplied USB-A end cable) to the USB3 Camera connection dongle .... and the BFPro powers up (yes, held the DIM/SELECT buttons to enable C.C. mode) .... sometimes .... if it doesn't power up a "click" sound can be heard repeatadley from the BFProFS .... and then after a bit it might power on, or might not .... unplug the USB cable and replug and in most cases the BFProFS powers on and runs .... the only issue I have struck so far (no monitors connected yet, just headphones) is that if the headphone volume is raised to close to 0dB on the fader, the BFProFS crashes/shutsdown/reboots ....
The powerbank A or C outputs provide more power than the BFProFS requires when running on USB power and I believe the issue is with the Apple USB3 camera connection dongle not passing sufficient power through when driving headphones at higher levels .... iPad charges, BFProFS works (did a 6hr session learning in/outs of TMEFX yesterday using 2 tracks input using the powerbank as my only source of power) .... ran without a hitch unless I really pushed the headphone levels ... did note the UBS3 Camera dongle got quite warm to touch ... not hot, but warm enough. The USB-A connection on the powerbank seemed to be more tolerant of headphone level than the USB-C connection on the powerbank and took more volume before it dropped out and rebooted.
So, by my understanding an "I" device with a USB-C port should work direct connected ..... the required cable was even supplied with my BFProFS.
1st post / new user / learning the ropes
Kevin.