How can I get more 'slots' for the shortcut buttons? I like a lot of them, and I really want to use plenty. I can do away with copy, cut, paste and undo because the keyboard shortcuts are really easy to remember. But just 2 or 4 more would be really helpful.

Is there a way to get more spaces for the buttons? If so what is that way?
And can you make it a configurable option or point to a mod that has such an option so every player can select how many buttons they want? I have looked and couldn't find anything.

I know you can open the 3 dot menu and press the button there. But what's the point if you can just open the train and click manual mode just as fast?

I want more button spots please!

PS:
I've noticed in another threat that german was used. Why not to write bug reports in german even if both the dev and the reporting party are native germans:
The majority of the people in the world use english as an international language. It is therefore desirable for everyone to be informed about the bug, can search for the text description of the bug and read possible workarounds and get status updates. Most people in the world do not understand german. It's just not a good idea to use any language other than english in a multinational community (such as factorio players on the official factorio website).

First of all I'm always happy to hear from people using the mod! :)

The maximum number of shortcuts you can have in the shortcut bar is limited by the base game and it's 24. In my opinion that's plenty and there is no way to mod this except creating a completely new GUI. To get 24 you need to go to settings -> interface -> other -> shortcut bar rows. Set it to 4 to get the maximum of 24.

Also you can set keyboard shortcuts for all shortcuts added by this mod. Go to settings -> controls -> mods -> shortcuts for 1.1. For things you use rather frequently you will probably remember the key sequence soon enough.

As for the language: I totally agree with you. I think I even said something similar in the topic you mentioned (though ironically I wrote it in German :). But I also always try to communicate with people in a way they feel comfortable in. If that happens to be in another language than Englisch that I understand, so be it. It's better if people report a bug in Chinese (bad metaphor for a language that the average European doesn't understand), than if they don't report it at all. But again, I try to avoid it for the reasons you mentioned.