More then 8000+ annotation at that time app stuck

[jigs777]

Description
We are add 8000+ annotation on mapview at that time app stuck and memory used 160+ MB.

Screenshots
If applicable, add screenshots to help explain your problem.

Smartphone

• Device: [e.g. iPhone7]
• OS: [e.g. iOS13.3]

Checklist

• I updated Cluster to the latest version.
• I read the Contribution Guidelines.
• I read the documentation.
• I searched for existing GitHub issues.