@rumo: the idea with link in the tooltip was not well-thought-out and I can’t think of a good one-sentence explanation so the whole tooltip idea should probably be ignored.
One more idea about the different background-color: I guess the card mode would remain the default. So the note mode as the exception would get the alternate background color in the table. Maybe once the note button is activated/clicked its background color could be changed to the same color as in the table. This could give you a visual hint that the table state is related to the note button?
About the “wasted space”. If we already add another row for the notes/cards button we can as well fill it with other stuff. Maybe more buttons?
Since .41 removed the buttons for filter, search, preview from the search row a row just with buttons might be useful? In general @AnKingMed advocates for the inclusion of the fastbar add-on and I guess he gets lots of feedback from ios users. Maybe a button could be shown that allow to toggle the full fastbar (which was built-into 1.x).
More table related but less popular maybe a function from my Table/Editor side-by-side (horizontal split) or even less popular a function from my Browser Maximize/Hide Table/Editor and I guess there other ideas out there. To be clear I’m not advocating to include anything from my add-ons - from a maintenance perspective I prefer minimal changes to the browser. These were just the first ideas that came to my mind: for me a toggle that decides what’s shown in the table feels pretty close to buttons related to the position or size of the table which for me is related to toggling UI Elements in general. I don’t know how useful these would for a wider audience.
Figuring out how to best fill the new row and convincing Damien of such a big change might mean we never get it. So maybe a new row can be avoided altogether? Since .41 removed the buttons for filter, search, preview from the search row maybe now there’s enough space to move the radio buttons (or a slider) to the same row as the search bar?