Environment Variables in Drawing Sheet file path crashes Python plugin invocation from script

We use a company specific drawing sheet that is distributed via git by using
${KICAD_USER_LIB}\template\company.kicad_wks in the Page Settings dialog.

When using the HTML BOM or KIKIT plugin I get the following error:
grafik

When I add the complete path not using the environment variable it works.

When browsing to this path KiCad will substitute the absoulte path by a defined environment variable if defined. Sometimes this also happens when the path is manually entered, but I cannot reproduce.
There seems to be a routine that parses the filename after pressing return in the file name box.
My current workaround is to manually fix the file name in the *.kicad_pro-file:

 "page_layout_descr_file": "C:/kicadlib/template/company.kicad_wks"

Both plugins are Python based, will this issue also be present in V9?

I am using

Application: KiCad x64 on x64
Version: 8.0.7, release build

on Windoze 10