Qml plugins javascript import broken

OS: Windows 7, Arch.: x86_64,
MuseScore version (32-bit): 2.3.2, revision: 4592407
Portable Build

Qml allows importing javascript (http://doc.qt.io/qt-5/qtqml-javascript-imports.html) files in the form
import “myFile.js” as Myfile
where js file path can be either an absolute or relative path.

Indeed back in 2012 (https://musescore.org/en/node/17581) it looks that Musescore was able to handle both absolute and relative js imports.

Now something has broken.
If I import as absolute,
import "file:///C:/local/music/MuseScorePortable/Data/plugins/scoreFuncs.js" as Sf
the plugin runs either from the “Plugin Creator” and from the “Plugins” menu.

If I import as relative import "file:./Data/plugins/scoreFuncs.js" as Sf, (Qt.resolvedUrl("./") shows the current directory is C:/local/music/MuseScorePortable), the plugin runs correctly from “Plugin Creator”, but when I try to enable it from “Plugin Manager” its details, version and descriptions do not show in the right panel and the plugin is not shown in the “Plugins” menu.
This is a regression respect to what shown in 2012 post.

Another question, I’m not a Qt programmer so may be there is an obvious reason, but I didn’t understand it. Why do I have to use the file: syntax for the import to work?
I found this https://stackoverflow.com/questions/45484222/qml-import-external-javasc… , I simply tried it, and it works, but I really didn’t understand what those posts are talking about.
Beside back in 2012, as shown in the cited post, it looks there was no need to use file: syntax for the imports to work.