Minor edits are something that we don't want, even less so from <1k users. The whole idea behind the suggested edits review queue is that new users learn and understand how to edit, what to edit, and when to edit.
In fact, this rejection reason exists to discourage new users from making the very type of 2-3 character edits such as capitalisation and punctuation (mixed with other unnecessary changes to cross the six-character limit), which do not add any value to the post.
Once users gain the necessary reputation points which grants them the edit privilege, then they may choose to perform such edits as they do not end up cluttering the queue and taking up other people's time. However, the fact that they should have by now understood that minor edits are generally not acceptable, means that they will too, edit posts only when they are adding value by addressing multiple issues.
Minor edits (as marked by the original editor or one of the reviewers) would go into the other piece. Minor edits will allow the editor to bypass the six character minimum.
Your feature request asks to make this type of editing legitimate, something that is undesirable for Stack Overflow.
Even if such edits did not make the post go back to the main page, you would still be cluttering up a queue full of trivial edits which add no value to the site and waste reviewers' time. Time, that could have been otherwise well spent on value additions to the site.
Also, if these are made out to be legitimate edits, there would be a explosion of these on Stack Overflow as almost every post has 1-2 characters worth of editing to go in it. Be it a space, a missing punctuation mark, or anything else. So, we would end up pretty quickly with a queue full of 1k to 2k reviews (conservative estimate) waiting to be done, most of them useless.
Thirdly, an excellent training opportunity for new users to properly understand the review system and to use editing privileges with some degree of responsibility would be lost. As edits by 1k+ users would still go directly to the home page, attempting to solve one "problem" would cause a much bigger much worse problem.
Also, if your next feature-request is about allowing 1k+ users to make edits which do not go to the home page, then that is a bad idea. That would essentially be opening up Stack Overflow to vandalism and spam all over (a user could easily edit in adverts into old popular posts without anyone knowing).