The wiki states that:
There are 100 pages of buttons, each (by default) containing 100 buttons in a 10 by 10 arrangement.
I would like to have more that 100 Buttons per Page.
I can change the grid size, for example to 15x15.
Tho the button count stays at 100 per page.
I did not find a way to add more buttons per page.
As you already stated, there are 100 pages of 100 buttons per page. You are not able to add more buttons to a page, even when you change your grid size.
Now for a work-around suggestion. If you are changing your grid size to smaller buttons / different layout. You have created more space in your window. You are able to edit your view and change the size of button window (make it smaller) and then add a second button window in the space. You can set button window 1 to page 1 and button window 2 to page 2. Save your view. You now have a view with 2 button windows can now have up to 200 buttons in view. Or as many as you have room for in your created workspace / view.
Would be cool to have the option to have more buttons per page in a future onyx release Or even cooler, be able to put buttons into the 2D Plan to create something like a custom button layout like MA has.
You might also consider exploring the ONYX “Manager”. On YouTube there are some quick examples of you search “ONYX Manager”. That might give you an idea.
Disclaimer - I have not used this piece hardly other than knowing it exist and is a “third party” type application from one of the original developers.
ONYX currently cannot have more than 100 buttons per playback page. This is due to the fact that these playback buttons can be configured via the command line, using IDs 1 thru 100 for each page.
However, I have logged your suggestion of allowing playback buttons to be added to the 2D Plan (reference number ONYX-1128).