Increase the amount of aggregated devices / best practice

Hi guys,

just two quick questions:

1)
Running a VC of 3 EX4300. I will need to increase the amount of aggregated interfaces.
Can I increase the amount of aggregated devices within the config during normal operation, or will this lead to an impact of the currently running
aggregated interfaces ?

2)
What is the best practice for working with aggregated interfaces ?
Scenario A) Increase the amount of aggregated devices -> commit -> add the AE-Interfaces and assign the pyhiscal interfaces to that ae-bundle -> commit
Scenario B) Increase the amount of aggregated devices / add the AE-Interfaces and assign the pyhiscal interfaces to that ae-bundle -> commit (all within one commit)

Thanks !

Regards, Christoph