mash_graz, thanks for reply.
Regarding your comments on ‘L’, and ‘O’ - I agree. However, if an application offers the user a comprehensive keybindings settings feature, then the default keybindings are never part of the UI design. They are the right and responsibility of the user to configure. If we can agree on that, then we never have to discuss them anymore. To illustrate, don’t you agree that once user documentation starts in earnest, the documentation’s source text should always refer to the key binding (‘shortcut’) name, not the default value?
Regarding your earlier words : "i think, viewer nodes in open-fx pipeline can be seen as leaf-nodes that trigger the flow of processing through all nodes beyond them" - that sounds interesting but I don’t understand. Can you shed some more light or point me in the right direction to learn more?
Also, regarding your statement: “in the most usual case, you have only one viewer and its including timeline on the screen” - this is true but we want to go far beyond the typical case: because the viewer is so big a part of a compositing app, we want it to be very flexible. We need to give power tools to experts and avoid designing for the ‘lowest common denominator’ among users.
So, regarding “why should we change something that brings more disadvantages than benefit?”, the answer is we only want to hide redundant timelines and somehow do that without losing any capability, or else better not do it.