Hello Pusheen the cat!
We hope your browsing have upgraded with the islands. And thank you for sharing your feedback about closing island tabs all at once.
We value all input and hope to receive further comments on similar experiences.
As we test the option to close islands at once(destroy), we are also considering an alternative solution: archiving the islands(sink) so that the island tabs become searchable even if the island is no longer present on the tab strip.
I wonder what Schrodinger's cat would go for 🐈
You can see upcoming features here among some other improvements we plan to release.