Yeah, but... I haven't given the preset lists any thought, mate.
As you correctly understand, I was only offering a way to be able to "scroll" through the category "headings" at the top of the page. I don't know how many there are, but I know there are more than 4, which is why I suggested it.
As for how this scrolling might affect cursor position in the preset lists, I think it shouldn't do so; after all I'm suggesting the page buttons should only scroll the headings (categories) at the top of the page. Only those four words need change; this would minimise confusion until a new category is selected. There could be an option to update the preset lists in line with category selection, or just to "freeze" the current position whilst a new category is being selected. I say this 'cause sometimes you want to see some preset names when you browse categories, and other times you don't... I think.
So, the arrow up / down / left / right buttons below the page buttons could be used to quick-navigate the preset lists, as they are for Rigs, and the Page L<->R buttons could be used to move to the next / previous 4 categories as named under the soft buttons.