I had been experiencing significant performance issues, as well, as consuming a lot of mobile data when using JasperSoft Studio, which have now been resolved.
The summary of settings suggested in JasperSoft Studio are:
1) Enable "Disable Expressions evaluation" checkbox and it will significantly improve opening up report with Jasper Studio 7.1. (This new security preference is not in Jasper Studio 6.2.)
Navigate to Jasper Studio 7.1 menu bar->window->Preferences->Jaspersoft Studio->Global Settings->Jasper Studio->Disable Expressions evaluation
2) For other performance concerns: The default ram allocation in Jasper Studio 7.2 may be small. To increase ram allocation, edit "Jaspersoft Studio Professional.ini" and try to up the ram allocation like as below.
-Xms2048m
-Xmx4096m
Reference: https://comm.support.ca.com/kb/ppm-very-slow-for-opening-up-reports-using-jasper-studio-7-1/kb000125070
3) Turn off Automatically find new updates and notify me.
Install/Update - Automatic Updates
Turn of Check for updates on startup - Jaspersoft Studio
My personal view to disable these.
If you are experiencing performance issues using JasperSoft Studio, in particular to Open or Publish reports, please consider the above settings.
Thank you to Jeet from CA Support for assistance on this one.