There are a large number of outstanding pull requests on the main ExcelJS repo https://github.com/exceljs/exceljs/pulls
It would be useful to review and resolve these. The following analysis reviews all open PRs and groups them based on
- complexity (easy vs hard),
- completeness (PR includes tests, examples, etc.?),
- salience (number of people commenting, number of comments, importance of topic)
- type (e.g. bug/enhancement/new)
https://github.com/protobi/exceljs/wiki/Analysis-of-open-pull-requests-in-ExcelJS