You are correct if I now understand that you want to upgrade video cards from the standard, as even OS4.1 Classic supports the AGA chipset.
The issue that he and Everblue were worried about, is that the old version of the RadeonHD driver on the original AmigaOS 4.1 CD doesn't support Radeon HD 5xxx+ cards. This is a big deal, because if your card isn't supported, then you cannot install the OS; your install CD won't boot.
Radeon HD 4xxx cards are no longer made, so more and more people have Radeon HD 5xxx+ cards. It would be unacceptable to expect users to find and plug in an old graphics card, just to install the OS.
Hence, Amigakit asked me to create a lite version of the driver especially for the new install CD. This allows the CD to boot, so that you can install the OS (and your licensed full copy of the RadeonHD driver, whether that's version 1.x or 2.x). Problem solved.
Hans