I'm hoping I can create an automation rule that:
when a new subtask (a subtask type specifically created for this)is created it is automatically linked to issues that are in a particular status AND have a particular field set, so for example:
Rule is along the lines of when subtask X is created, link to any issues in status "testing" that has the custom field of ready is set to "yes", so if there are 40 issues in status "testing" but only 4 have the ready field set to yes, then it would link the 4 issues.
Add to that if any of the issues in status "testing" are changed after the inital subtask is created, the ready field is set to yes then it would link to the subtask originally created
Might be a tall ask for automation but lets see if it can be done.