Cannot add rows to table that is pulled in from cross-doc

I have double checked that I am using “Read-write access to [table] within [source doc]”, yet when I use the Cross-doc Add Rows formula I get the error :
You don't have permissions to take this action in Cross-doc

So what is the recommended way to Add and Edit rows from the source table in one or multiple other target docs ?

In standard Coda you need a workaround to write back from a destination cross doc table to a source cross doc table.

Check out Paul Danyliuk’s improved cross doc pack in the pack gallery. It should solve your problem