Should I wait before my LORs are in the ADT system or apply right away?
In most cases you want to apply without waiting for the LORs to show in the ADT.
First of all, there is always a delay between the moment LORs are available and the moment you can see their records in ADT. In other words, you do not really know they are there until you apply.
Secondly, if you are targeting September application, programs won’t get to your documents until end of September – early October. But they will use your place in the queue, so applying early does matter. By the time they get to review your application, LORs will be already there.
Finally, most programs do not start reviewing application until it is marked as “complete”, i.e. has all the documents properly uploaded. So, in the worst case scenario, your application will just be on hold until the LOR(s) become available.