plasma5 screen management going wrong

[Bug Reporter]

see below

On Fri, Jul 13, 2018 at 2:35 AM, Duncan <1i5t5.duncan at cox.net> wrote:
> Bug Reporter posted on Thu, 12 Jul 2018 22:00:58 -0400 as excerpted:
>
>> The lack of powerdevil may be the showstopper in this process. So I
>> started looking for a config file that might disable kscreen. I did not
>> find any yet, but I did find kscreen-doctor. This might be the way to
>> leave kscreen installed and to manage it the way one would manage
>> screens with xorg conf files or with xrandr.
>>
>> Interestingly, `kscreen-doctor -i` tells me: Preferred KScreen backend :
>> KSC_XRandR.so
>>
>> KSC_XRandR.so: /usr/lib/qt/plugins/kf5/kscreen/KSC_XRandR.so
>>


I like xrandr as well as arandr (GUI). Now that I have some additional
experience using those tools, I would like to disable or remove
kscreen. As Duncan suggested, this seems to be a good way to solve my
screen management headaches. I can apply layouts manually using xrandr
(with an alias or script) or I can use arandr, which has all the
features I used in kscreen plus more (e.g., saving and restoring
layouts).

Having both kscreen and xrandr / arandr appears to create conflicts.
In some testing I just did, arandr would not apply a screen layout
while kscreen had the monitors disabled. We had to use kscreen to do
the task. Without kscreen installed, arandr worked perfectly.

However, I do not want to remove powerdevil, therefore, I cannot
remove kscreen. I looked at laptop-mode-tools and I did not like what
I saw. It looks very dated. I'm not confident it will work that well
on modern hardware. For example, I'm running NVMe drives. I don't want
to get diverted from the task at hand by having to solve a bunch of
power management issues, so powerdevil has to stay installed -- but I
want to disable kscreen.

In addition to KSC_XRandR11.so, which me mentioned previously, I see
KSC_Fake.so, and that prompts a question.

# ls /usr/lib/qt/plugins/kf5/kscreen/
total 504
drwxr-xr-x 1 root root    136 Jun 27 12:50 .
drwxr-xr-x 1 root root    490 Jun 20 21:45 ..
-rwxr-xr-x 1 root root 100176 Jun 26 09:15 KSC_Fake.so
-rwxr-xr-x 1 root root 104360 Jun 26 09:15 KSC_KWayland.so
-rwxr-xr-x 1 root root  67408 Jun 26 09:15 KSC_QScreen.so
-rwxr-xr-x 1 root root  75600 Jun 26 09:15 KSC_XRandR11.so
-rwxr-xr-x 1 root root 157608 Jun 26 09:15 KSC_XRandR.so

What would happen if I copy KSC_XRandR11.so to KSC_XRandR11.so.bak and
then copy KSC_Fake.so to KSC_XRandR11.so? I wonder if that would
render kscreen "disabled" while leaving it installed. Any thoughts on
this?