Export and overwrite pages on import?

You have a narrow selection to choose from. Either replace the database tables with something like wp-cli or have a special import-export process for your data.

If you want to make this granular, you could make a post metabox to import/export post content and metadata as json. Then updates could be incremental and on the fly.

But if you develop locally on a different database, then you run the risk of your post IDs being out of sync. So keep that in mind during import/export in any way you choose.