They are verified at the county level by republican and democratic workers that don't know the ballot vote before approving or denying an absentee envelope based on signature. There is no need for "independent" verification as they can't be approved or denied based on vote bias to begin with. On top of that, county level election officials from both parties have said that there was no evidence of fraud. Along with the Republican Governor, Republican Lt. Governor and Republican SoS. The kind of coordination across parties at multiple levels to even achieve a marginal difference WITHOUT leaving a trail or evidence requires a tinfoil hat to even fabricate, let alone believe. As to the political score for Georgia, it has been under republican trifecta control since 2005. So, you are implying that a corrupt state government would coordinate against its own presidential candidate for reasons unknown.