is there a limit to a maximum column width?

Hello,
 
Thank you for your question.
 
Currently, the maximum column width is 480px.
There are no available options to change it from the outside.
 
Please let us know if you have any questions.
 
Best Regards,
Vera

Hello,
 
We are glad to inform you that we have found an approach for your case.
 
It’s possible to override maximum column/row width using CSS classes .fm-grid-column/.fm-grid-row:

#fm-pivot-view .fm-grid-column {
max-width: 300px;
}
#fm-pivot-view .fm-grid-row {
max-height: 300px;
}

 
Here is a JSFiddle example for illustration.
 
Please let us know if this works.
 
Best Regards,
Vera