Realtime Client can subscribe multiple times to same channel

Use Case:

I have a page which has a table of objects.
When clicking on an object in the table, a modal opens.
The user can perform an async task on that object.

When the async task is running, the modal shows a loading spinner.
The table on the page also shows a loading spinner (in case the user closes the modal and comes back later)
In my async task queue, I send a broadcast realtime update when it's done.
Ideally, both the page and the modal receive the update and remove their loading spinners.

Current Behavior:

I've found that the client cannot subscribe multiple times to the same channel. As soon as the second connection is established, the first no longer subscribes.
This is also confirmed here:

Possible Workaround:

A channel manager middleware. I'll post it in the comments

Ideal Solution:

realtime-js allows this natively