I've added 3 screenshots. The first is my app using 100% dpi in the Windows 7 VM (with VirtualBox scaling at 150% to make things visible). You can compare it with my earlier screenshot and see the difference.
The next two are for your demo program, the first at 100% dpi and the second at 150%. So, no, your demo program does NOT scale correctly for me. The heights of the widgets are okay, but the spacing is messed up. This messing up applies to the compiled file as well.
If I compile at 100% dpi (in the Dev environment), the program is fine and scales correctly at runtime on high dpi. If I then close Lazarus, change the Windows 7 dpi to 150% or 175%, reboot, and then open the project in Lazarus again, it gets messed up (and changing the Project Options, before or afterwards, makes no difference).
Note that I previously used my VM for a non high dpi machine. It may be that the Lazarus IDE somehow records the dpi when installed, so I can perhaps check later if this has any effect.