With a Dell laptop charger connected to the Delock hub:
purism@pureos:~$ cat /sys/class/power_supply/tps6598x-source-psy-0-003f/uevent
POWER_SUPPLY_NAME=tps6598x-source-psy-0-003f
POWER_SUPPLY_TYPE=USB
POWER_SUPPLY_USB_TYPE=SDP DCP CDP C [PD]
POWER_SUPPLY_ONLINE=1
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_CURRENT_MAX=2000000
POWER_SUPPLY_VOLTAGE_MAX=5000000
With the Librem 5 charger connected to the Delock hub the Librem 5 receives the same amount of power (initially I had written that with the Librem 5 charger the hub did not provide power, but now it appears that that setup does work).
The Librem 5 charger connected to the Librem 5 gives:
purism@pureos:~$ cat /sys/class/power_supply/tps6598x-source-psy-0-003f/uevent
POWER_SUPPLY_NAME=tps6598x-source-psy-0-003f
POWER_SUPPLY_TYPE=USB
POWER_SUPPLY_USB_TYPE=SDP DCP CDP C [PD]
POWER_SUPPLY_ONLINE=1
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_CURRENT_MAX=3000000
POWER_SUPPLY_VOLTAGE_MAX=5000000
The Dell charger connected to the Librem 5 gives the exact same output as the Librem 5 charger.
The video signal through the hub over hdmi to the 4k display is perfectly stable. It seems hard on the Librem 5 though: mouse and keyboard input is not exactly snappy.