You can thank the NES for the 30-row support (and a few other enhancements). Keep in mind that when all 30-rows are enabled, the name tables are larger. Pixel scrolling is also available in T80 mode, but not the multiple pages. Unlock the F18A and set bit >40 in VR49 (as shown above, thanks PeteE), and you will have 30-rows available. The Text modes also have the "position-based attributes" available.
Note that in the next F18A firmware (yes, there is going to be at least one more, if not two, updates), Sprite Linking and the Real Sprite Y position features are going away. I only mention those here because they are part of VR49.