What problem does this address?

The RTC polling client currently runs at these frequencies:

• Once per second if no other collaborators are in the room
• Four times per second if other collaborators are in the room
• A couple of back off rules apply for the following circumstances:
  • An error occurs while syncing
  • The editor is not visible, ie the user is using another browser tab

As these rates generate a large number of requests, it may cause problems for users of low end hosting plans and result in them inadvertently DDOSing themselves.

See Discussion on WP#64845

What is your proposed solution?

Add filters to the polling intervals defined in this block of code to allow third party developers to slow the syncing rate as desired.