It totally depends in what context you are at.
You are testing an electronic device that will be shipped with the software you are testing. After your approval, nobody else is going to test it. End users are only able to update the device by connecting it to a PC.
In this context, it is highly important that the result of your testing (and rework) is that the software is as perfect as possible, including any typo's or spelling mistakes that you see. Not correcting them will possibly give a bad customer experience to a lot of customers and it it will take a lot of time before all of the users have updated their device.
You are working on an eCommerce platform. While testing, you see that one of the existing information pages of the website contains some spelling mistake. You observed this on the test environment. The content is managed by a team of webmasters on the production environment and there is probably hundreds of pages with content like this. Content like this is really the responsibility of the webmasters team and should not distract you from the work that you were really doing. Your issue might not even be valid, as the content could be different on the production environment.
You are still working on the same eCommerce platform as in case 2. While testing a new feature, you see that one of the text labels related to the new feature is incorrect. For end users this would cause a lot of confusion. As you know that the label was just created by your team and you also know that it has to be fixed anyway, report an issue straight away to make sure that the label will also be correct when deploying to acc and prod environments (and thus prevent further overhead).
In case there is a lot of critical/blocking issues that really require more attention right now and the release is under high pressure, you could also choose not to do anything with the issue and then walk to the webmaster team just after go live and ask them to correct it.