For most schools as long as you dont click submit, your application wont be submitted and the LOR's usually are with your application. They wont really care if they receive the LoR's early.
I think what fugo says is true for most schools. Your LOR's and application will be there until the end of the current application year. Until you click that submit button, the school won't know whether you are applying for R1, R2, or R3 etc.
Some schools send out warning before the end of the application year with a message telling you that all the information (including the LOR's) will be lost if you don't submit the application by the last deadline.
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