TL;DR: It's fine - it's tested and it still works.
Bringing attention to the notice on the plugin page, saying:
This plugin hasn’t been tested with the latest 3 major releases of WordPress. It may no longer be maintained or supported and may have compatibility issues when used with more recent versions of WordPress.
Despite at time of writing there hasn't been an update in 6 months, I have tested this and in my experience (I am working to add E2E testing for better verification) - it does work, and although inactive on enhancements I am still supporting the plugin.
Supplementary consideration - a better way to update the "Tested up to" that doesn't require pointless deployments?
TL;DR: It's fine - it's tested and it still works.
Bringing attention to the notice on the plugin page, saying:
Despite at time of writing there hasn't been an update in 6 months, I have tested this and in my experience (I am working to add E2E testing for better verification) - it does work, and although inactive on enhancements I am still supporting the plugin.
Supplementary consideration - a better way to update the "Tested up to" that doesn't require pointless deployments?