Otherwise you would get weird situations where people could apply to distant jobs and the employer having to pay those costs and hours. Get a job with a 2 hour one-way commute and you would then only need to work 4 hours… obviously not going to work.
The obvious solution is to limit it to the historically normal commute time (30 mins to 1hr each way)
You can choose to live 4 hours away, but the organisation only pays for x hours
I think the minimum commute time available to a young family person in my town now is 45 mins, so that would be an obvious limit here