Is there a way to disable UAC prompt while running as admin, and if there are any other downsides besides the one mentioned in the prompt? As I see that apps run from dock, are still run in non-elevated session, which is good.

NO THEY ARE NOT! Anything launched from an elevated application runs itself elevated, which is a MAJOR security risk and a HUGE NO-NO.

DO NOT run Nexus elevated, there is no need nor any reason to!!!

hmm weird, as I've run terminal and it wasn't running as admin, thanks anyway

Well, here's a weird thing that I've encountered. In my Admin a/c on the 'new' quad i5 Win 10 weird build, when something needs to run elevated it asks to confirm or deny, and ordinarily seems to run non-elevated. Queer!

Open the Windows Task Manager, go to the Details tab. Right click one of the headers and then click on "Select Columns". Scroll down and enable "Elevated" then press Ok. This will allow you to know if an application/process is running elevated or not.

Now launch an application from an elevated session of Nexus (e.g. Notepad). Check the Details tab in Task Manager to see if that application is running elevated or not.

I just tried it here (just in case Microsoft had changed yet something else I did not know about) and the Notepad executable launched from the elevated session of WorkShelf was running elevated as well, just as expected.

Well, I tested this. A bunch of apps started from an elevated Workshelf were running non-elevated according to Windows Taskmanager in the Admin account. When I started an app that triggered the message that it needs to run elevated and I clicked 'cancel', it just didn't run. So M$ probably had changed something in this build of Win 10?

Doubt it. There are certain specific circumstances where an app launched from an elevated app might NOT run elevated itself (also if you have an item in the dock or shelf that has the 'run as admin' setting enabled it will ALWAYS ask for elevation, and if you click Cancel at the UAC prompt it will not run), but it doesn't matter anyway.

You simply do NOT run a Program Launcher with elevated privileges EVER (even more so when said program launcher really does not need you to), this is basically asking for your system to be p0wned.

Very odd then...

No part of Winstep is normally running elevated even in the Admin account, BTW. Almost nothing is except when specifically demanding it.