Seems rather an expensive way to do it - especially since if it is a native DP monitor, it is probably a fairly decent one.
It is an exceptionally good one, which was why I was trying to make use of it...
The monitor, by default, is used with my desktop. What I have done, is install RealVNC on the desktop, which now enables me to take control of the Rpi, and it's display, on the desktop.
Usually the prices here are too high. I use the site
for an "existence" check, to see if an item is made.
"Active HDMI to DisplayPort 1.2"
https://www.startech.com/en-ca/display-video-adapters/128-hdmi-displayport
Chipset ID Lontium - LT6711A
*******
This looks like a cheap one. Helpfully, they labeled "source" and "display"
so you know which direction of conversion it supports.
Active HDMI to DisplayPort Adapter (***@60Hz),
Uni-Directional HDMI Source to Display Port Converter Cable HDMI Male to DP Female
https://www.amazon.co.uk/HDMI-Adapter-Uni-Directional-Male-Female-Grey/dp/B0DHXFKZGM
There are some Club3D branded ones, and that "branding" (which used to be
a video card company at one time), makes a few different models. Some with
better specs than others.
The USB +5V supply is "optional". It can be thrown in as a cable, when
the chipset manufacturer refuses to bound power consumption, and the
USB cable is the "auxiliary supply" in case it does not work. By using
the USB cable, it should stop drawing +5V from the HDMI source device,
and instead draw it from whatever provides the USB power.
Generally speaking, the higher the resolution requested, the warmer it is
going to get. Run at 1920x1080 @ 60FPS, it's possible you could leave the
USB cable dangling. The display resolution and refresh determines the datarate
on the cable.
The EDID from the monitor, should flow back to the source device,
and the source device defines the resolution and refresh. I use several
adapters here for monitors, but the type you are getting, I have
zero stock of those. If for any reason, the EDID signal did not
go back from the monitor to the source device, the source device
will select 1024x768. If circles look like ellipses or such,
then it's an EDID issue. An EDID dumper program can be used
to see what resolutions the monitor supports (the "native" res
giving the best picture).
Paul