Limiting Job Imports: Understanding the 'Find Jobs' Source Limitations

When using 'Find Jobs' source, why do I only see 50 results once I limit 1 per company? There is definitely more, but for some reason I can import only 50 at once. Is there a way to unlock this and import 1000 unique companies located in US that have posted a job 'Lead Generation Specialists' in last 20 days?