Is there a way around the following, or a good explanation why it is this way …
The GLSL shader has a “text” input which one can enter text, sure not a full editor but one can manage/choose to use that or something external. BUT, nodes like “Append texts” while it also has a “text” input does not allow the same editing, for example I cannot use the return key to create a new line.
Damn, surely I tried that … obviously not. Thanks.
So that is the solution, but why is there different behaviour of text input between nodes, seems confusing.
The different behavior is meant to streamline the most common usage for each node. For most nodes, the text input editors behave like other types of input editors, with Return accepting the input and dismissing the input editor. For Make Image with Shadertoy, obviously the Return key is essential to editing the text, so Return makes a linebreak and you have to click away to dismiss the input editor. (This comes from the "isCodeEditor":true in the node source code.)