Not issue, it's an update suggestion: enable inverting selection

[tedomedo]

I want to select all chunks where i have my buildings and other needed stuff, invert selection and delete all other chunks. This would be easier since there are 90% of worthless chunks in my .mca files.
If inverting is already available then let me know how can i do this.

[TheMolkaPL]

Have you tried using mcaselector? It suits better for what you are trying to achieve.