Microsoft doesn't support anything in the Resource Kits, officially, because they don't perform any security testing on the components, nor do they provide any ongoing updates even if security issues are identified.
Clearly, that's not the exact case with Kixtart, as Ruud has been supporting and updating this since the original release.
As for the reg hack, I've never deployed it at any customer site, nor have I deployed it internally. I've never had issues reported with drive mappings, and my script has been deployed at several large schools as well as several global organizations (the largest having nearly 30,000 users). While I can't attest that admins at sites where the script is in use but I don't support haven't deployed the reg-hack, I'd expect that they would have first reported a failure of the script to map drives, and that has not happened.
Glenn
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Actually I
am a Rocket Scientist!