Exploratory testing - modifying test steps and test cases during test run

So the tester executes these tasks in parallel:

- executes test cases

- modifies/adds/removes test cases, executes tests that were added/modified

- modifies/adds/removes test steps, executes test steps that were added/modified

Can it be done in Spira? Now I see that when you run "Execute" of some Test Set - then all the tests are _copied_ to the test run, so when tester adds/modifies tests and steps - he/she cannot run them since new changes cannot be promoted to existing test run. Test Runs are like "cast in stone".

As a result of test session - "Test Cases" part of the system contains added test cases and added test steps that were actually executed, some passed some failed - but nothing about them is in the Test Run part

running SpiraTeam v4.2.0.7