H1b Amendment (plus) extension move timing

If an amendement is filed and approved for a new MSA location within same state, do we have to start immediately working from the new location as per the LCA start date? Is there a buffer period like 1 week or so, where we can still work in old location as we plan on travelling to the new location?

If the old location’s approved H1B has not been withdrawn explicitly by employer, then it stays valid till the date mentioned on it and you should be able to keep working at old location till it’s validity.

Does it not over-ride the previous approved petition? Could you please clarify. Is there an resource or link you can point me towards?