As far as I know there isn’t an official way to increase the pin data size limit.
The limit is hardcoded to help keep the editor responsive and prevent performance issues.
If you need to work with larger datasets, you’ll need to consider workarounds—like storing the bulk of your data externally (in a file system or database) and only pinning a subset in the workflow.
You can also use subworkflows to process data in smaller chunks.
I’ve found a recent post about the same topic. Maybe you’ll find this useful: