Yes, improvements are continuing to be developed. However, I would encourage you not to get too hung up on the exact score, as long as it's not close to zero. AI detection software can produce very different results from one solution to the other. Please, always do a quick read-through of your article and view yourself as the editor, correcting anything that seems repetitive or out of place, prior to checking the score. The official word from Google shows they are not against AI-assisted writing, they just don't want content that appears spammy:

https://developers.google.com/search/blog/2023/02/google-search-and-ai-content

In the meantime, please try using some of these tips:

1.) Test whichever AI detection software you use against articles found on the first page of search engines, for keywords you are targeting, to ensure the AI detection software you are using aligns with what is actually being ranked well by search engines.

2.) Try bumping up your Difference and Unique filter as close to 100% as possible.

3.) Turn on all of the "Targeted Parts of Speech" under the Paraphrase dropdown, except for "Foreign word", "Proper noun, plural", "Proper noun, singular", and "Named entities"

4.) Add commonly used words such as (and, it, the, etc...) to your Preserved Words list if the other suggestions don't seem to work.

Best Regards,
Ben