The current wording on the too minor suggested edit reason is
Too minor: This edit is too minor; suggested edits should be substantive improvements addressing multiple issues in the post.
But I believe the majority of suggestions rejected under this reason aren't rejected because the edits are too small per se but because they leave in other glaring errors.
I might accept a suggested edit to correct a glaring typo in the title or indented the code if the remainder of the question is good, but I would reject (or improve if appropriate) a suggested edit that corrected the title typo or code indentation but left the rest of the question in an obviously horrible state.
So its not just the size of the edit (although that is a consideration) but also the percentage of the errors corrected that is considered. So I would propose changing the wording to;
Too minor: This edit is too minor or fails to address the majority of issues with the post; suggested edits should be substantive improvements addressing multiple issues in the post.