Are there any limitations regarding the processed data volume?

No, basically the Plugin can process any amount of data.

The only limitation are the known API limits of the salesforce environments you are using and the maximum memory size allocated to the nodejs processes.
If you are facing out-of-memory issues frist try to optimize queries in the export.json file.

For the common memory issue see I have an JavaScript heap out of memory error. How to increase?

Also refer to the salesforce documentation API Request Limits and Allocations

Last updated on Sa Oct 2022