In Georgia it's 100% legal to run for office in a district you don't live in. The carpetbagger angle won't fly and he has enough history in the area to use any accusations of carpetbagging as an excuse for Handel to try and distract from her record. She's much better off focusing on how he has worked for 2 ultraliberal Congressmen and is ultraliberal himself.
It may be legal....but the optics of Ossoff possibly using several addresses will not sit well w/ law-abiding Georgians.
Most people think using several addresses is a con game.....deceitful, trying to hide something.