OK. here's the word after I spoke to DJI. By the way, I got to a Spark Support Tech very quickly with hardly any time on hold.
I have yet to try the cable but I will. BUT, DJI said it's a s/w issue with iPhone iOS. They said not a problem with Android. Any Android users out there having the issue? HUGE latency, unusable. 1st they had me try switching from 5.8 to 2.4, it was LESS of a problem on 2.4 but still unusable and it switch automatically back to 5.8 as you can not MANUALLY set a frequency. Then he had me format the SD card, I couldn't figure out why but I did it anywhere and no difference. I am talking about video FEED latency.
Finally he said it would be fixed in next firmware update.