Performance factors
There are many factors not related to app which affects performance:
Excel version (Windows version and PC performance)
number of metadata schemes related to the differences in project (issue types, fields, field types, permissions), app pulls all data and before sending it to Jira makes validation
number of pulled issues and fields - app needs to render all that data in excel and this also requires time (there is no available way to disable pulled columns, meaning everything is fetched)
number of users actively using Jira in browser
Jira cloud availability
To increase App performance you should optimize this areas:
try do fetch issues from single project (not cross project, as it would fetch metadata from all used projects)
try to fetch same issue types (again different issue types and different screen configurations render more fields, taking your PC power)
disable option to group subtasks with parents
disable debugging mode
disable auto resizing
increase timeout time
when refreshing data, you can check refresh on selected rows instead of whole sheet
Things to optimize in Jira:
permission schemes in projects, the simpler and reusable its better
number of custom fields, try to re-use some of the fields instead of creating new ones
visibility of custom fields - even if custom field is not visible on create, or edit screen but it’s data still need to be pulled
Feel free to tell us what topic should be covered: excelconnector@psc-software.atlassian.net