None of our scope have isolated USB ports, we have tested a USB wifi printer hub (IOGEAR GUWIP204), let me know if need more information about this.
Most USB isolators and IC's only supports low and full speed data rates. (Low and full speed data rate: 1.5 Mbps and 12 Mbps)
And not the High Speed (480 Mbit/s, with USB 2), which normally runs at on a PC.
The scope will work at full speed -12 Mbps, with a USB isolator, when streaming (slow timebases -100ms/div or slower) maybe issue, but otherwise ok for block captures.
In block mode you may notice the waveform refresh rate to slower due to this lower transfer rate, but scope is still usable.
USB Power- You could use a powered USB hub with a isolated DC supply. The AC adaptor that comes with hub may already be isolated. You would need to check with a multimeter. This would still not be safe if you measuring mains referenced circuits. Only for working on CATI circuits.
It may pay to check what isolation ratings/standards the USB isolator has.
There are now some expensive fiber optic USB 3 isolators, but we have had reports from customers that they do not work with our PicoScope.
If do buy a USB isolator, it would be better to buy it from a supplier that you easily return if does not work with your PicoScope.