Never let your audience guess what you are trying to say, your writing should literally speak for itself. When your content has too many errors, it becomes difficult to read and understand. Although, one or two errors can be skipped by readers, but glaring grammatical errors can minimize the impact of your content. Also, it can make your writing difficult to read and digest.
This article spinner is known to have a team of friendly customer service representatives that are more than glad to accept any issues. Whenever theres a problem with the server or the system in terms of its features and functionality, then you can always escalate the problem to the best representatives available by submitting a ticket so that it can be resolved as soon as you reach out to them.
Imo it is not possible for google to detect properly spun content, it is not worth computing power it requires. They can do this using ngrams for example, but it is uses a lot of queries. And for example article spinner I coded beats this algo, so google cant detect that the content is spun. Manual spinning is also good but it takes more than 30 minutes per article.