In your java class you can convert the data to json using GSON and send back to frontend -Gson().toJson("data");

If it's minified then we can't do anything in aem rather you need to first convert it using some tool i thought it's not minified rather aem is minifying it.

If you enable debug checkbox then individual files you can see in console-Now access the page like below-http://localhost:4502/content/we-retail/ca/en.html?debugClientlibs=true You will be able to see individual files in console as below-If they are coming in minified version uncheck minify checkbox...

Please update below configuration so that files will not be shown in minified version-Post which if you will load your page clientlibs won't be in minified version.

Could u pls add the clientlib category as cq.authoring.dialog and check

Is it happening for a particular asset or all?

Just tried in my local server and it works fine(AEM 6.3) -http://localhost:4502/content/dam/hero-04.jpg.metadata-schema.json {"jcr:content/metadata/dc:title":{"label":"Title","value":null,"type":null},"jcr:content/metadata/dc:description":{"label":"Description","value":null,"type":null},"jcr:content...

No need to create dialog for classic ui as its deprecated..

Refer below thread-https://stackoverflow.com/questions/48424779/how-to-make-rss-feed-generator-for-asrp-blog-posts-in-aem-6-2

Previous log files are not deleted, so it is your responsibility to clean old log files periodically to limit the disk usage.org.apache.sling.commons.log.file.size controls the rotation of the log file by setting either:Please refer below link-Monitoring and Maintaining Your CQ instance