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Changes between Initial Version and Version 1 of Ticket #23216, comment 39

initial	v1
1	1	The first run uses the JS global `pagenow` to identify from which screen the XHR was sent. That is different from the PHP global `$pagenow` (in JS it is `$current_screen->id;`). Will rename it to avoid confusion.
2	2
3		Another consideration: if the user has two tabs open with the same admin screen, on the PHP side they all look the same. We can detect when a tab is ~~hidden~~ and throttle the requests, but we may still run into problems if several tabs are open (more than 10?). Should we make the "beat" very slow, perhaps every 2 min, or even pause it if the user is not on the browser tab?
	3	Another consideration: if the user has two tabs open with the same admin screen, on the PHP side they all look the same. We can detect when a tab is "blurred" and throttle the requests, but we may still run into problems if several tabs are open (more than 10?). Should we make the "beat" very slow, perhaps every 2 min, or even pause it if the user is not on the browser tab?