This is required for port Whonix from Debian stretch to Debian buster. Therefore have to revisit this now.
Neither kdesudo nor gksudo (package gksu) are available in Debian buster.
gksu REMOVED from testing says:
gksu is dead
pkexec seems not dependent on any desktop, but it does not support graphical (X11) applications by default. Making it work for graphical applications seems quite hacky.
pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY program-name
We’d have to create a wrapper for this since this is too much to type for users. But if we have to invent something for something as simple as this, it looks wrong.