I hadn't looked at that.... What you say seems to be accurate.....
But must admit that I occasionally have slow loads on DS CAM, on LTE data off my iPhone.... on 1x3 cameras.... (Set for 1920x1080/30) Having purchased only one extra License to get where I needed to be for my system here.... I've have allowed others in Mountainside Housing Development access to these cameras (3 of the 13 I own), so they can assess the road conditions on different surfaces: Blacktop Switchback; Grass; Rock Patio; and poured Concrete Driveway.... halfway up the main road on the mountain... These 4 surfaces react very differently to snow & Ice, and seeing this from a distant location can be very helpful in Winter, and change travel schedules!
Though I have my HikVision cameras prevented from accessing internet directly, via firewall rules.... I agree with you that with the HikVision iVMS-4500 software (Which I use on LAN Only) I do see 16 live cameras simultaneously... with that HikVision APP, but only 2x3 on DS CAM.