Several VBS files in guixt.ini: What is the correct way to specify more than one VBS file in guixt.ini?
Only the first file was read when I tried:

VbsLibrary C:\lib1.vbs, C:\lib2.vbs

I suggest you use a separate line for each .vbs file, e.g.

VBSLibrary C:\lib1.vbs
VBSLibrary C:\lib2.vbs

The single-line version that you use, i.e. comma separated list, is also possible but you need to remove the space after the comma:

VbsLibrary C:\lib1.vbs,C:\lib2.vbs