Again it took me some time to get it running. It contains hard card-coded paths for the ShellTreeView.Root which, of course, do not exist on my system. Only after removing this property from the lfm file I was able to run the project in both the 96ppi and 144ppi machines (in which the project was in different paths).
Besides the unusually large font size, I noticed the huge line height of the tree nodes. I reset the DefaultNodeHeight to 18, the startup value on a 96ppi system. Since, however, the VTV.Font.Size is at its default 0, the node text turns out to be too small in comparison with the other texts of this application. I increased it to 16, and the DefaultNodeHeight automatically adjusted to the value 30. Now it looks nicer - this is the state of the project that I am attaching.
Then I copied the project to a VM running at 144 ppi (150%). Loaded it into Lazarus, compiled it without any changes and ran it - no problem, the overall application seems to scale correctly, however, the VTV row height appears to be too large; the DefaultNodeHeight has been scaled up on the 144ppi system to 68. This looks as if it has been scaled twice: from 30 to 45 (150%) and then from 45 to 68 (151%). Therefore, I guess that the scaling of this property in VTV is not correct. Probably the DefaultNodeHeight is automatically scaled with the font height, and therefore no additional scaling must be applied to DefaultNodeHeight itself. I'll have a look...
You still did not tell me your Lazarus version, and which VTV you are using. LCLscaling of VTV has been added to the version in the Lazarus distribution about a year ago and thus should not be available in the Laz v2.0.x series, but in v2.2RC1 and trunk. It also has been ported to v5 in blikblum's GitHub repository (which is in OPM). All other versions of VTV do not support LCL scaling.