If people believe it threatens the integrity of the election then it already is a problem, whether it actually causes fraud or not.

Holding fair elections has no meaning unless people actually believe they are fair.

Also “abuse” doesn’t necessarily mean voter fraud. It can be as simple as being pressured by a family member to vote a certain way if you do it without privacy. If you vote alone in a booth that’s not an issue (and again - it’s an issue as soon as someone thinks it’s an issue).

Setting up mini polling places where people can cast early votes using the same procedure as on Election Day solves many problems without causing any new concerns. Other solutions have concerns however small.