Thanks for the reply. There is no such possibility, for additional custom block, unfortunately. You can submit a request here – https://www.8theme.com/taskboard/ If it takes votes from other customers then our developers will be able to add it to the queue.
If you are using Single Product Builder, you can activate Multiple templates and for different categories, and show the desired static blocks via Custom HTML elements – https://prnt.sc/1xkxo10
