"What's the issue," you ask?
The change of the DRM is understandable, but they've also changed the RTP install. With the classic style, we could use these methods to extend the RTP with our own entries. Is that even possible now? I'm stuck with...

^On my old Machine, I had Kain Nobel, Standard and Others, respectively. The planned final result is to have everything in the project eventually use the Kain Nobel RTP and not depend on the other two, but I'm unsure how to do that using the new install, which deviates from it's previous install path.
Now, for me, I've got a couple prototype builds for a massive project, using resources I've been working on for years. Many of these builds require said resources, and I really don't want to copy/paste the same files into multiple projects. I could, I have the space for it, but... it's just not proper.
So yeah... the registry has changed. XP's RTP is no longer located in the same registry path, only information I've found on it appears to be within uninstall data. What do I do now? Can I special request an older version of RPG Maker XP with an older version of the RGSS RTP? Please? The new one is blasphemy and it seriously irks me that they've changed it.
Thanks ahead of time to anyone who reads this post, double thanks to anyone who can help a brother out. I'm sure there are others that would be thankful too, especially if they're going full custom or bust like I'm aiming for, or if they've got an existing series which shares common, custom made, resources.