Is there a way to track ad spend cost accurately in tracker without API integration?

Hi, I am aware that the cost within tracker differs from the actual cost on the traffic source. I believe the reasons might be different timezone of two platforms, clickloss, and 'Do Not Track' browser setting.

The API integration solves this issue.

But the question is, if the cost token is in the URL then when the traffic source executes that URL to show an ad then shouldn't it pass accurate cost value to tracker?

The trackers do provide option to manually update the cost and match the timezone with trackers but theoretically shouldn't passing the cost through cost token parameter should be suffice?

I would like to learn if there's a way to track it accurately without API integration because some traffic sources don't have that feature.

Thanks