Content length limit i admin page?

A friend of mine that I helped setting up Grav seems to hit a problem with page lengths. He has created a very large markdown file size 70kb (that's about 22 pages of text). I had converted that from his older CMS and uploaded it via FTP. That works and the page shows nicely on the page. But he can't edit it as it won't save with the error that the content is not correct. I tested and found out if I remove some text until the file is 65706 bytes., it does save fine. But if I type one character more, the error shows up. This happens both on the hosting server as with grav server on my laptop. So it is not a limit on the hosting provider.
Question: Does Grav have a hard limit for the content length? If so, can I change that limit? If not, is this a bug or should there be something in my config?

See this issue on Grav's repo: 1.7.32: Why impose max sizes for field types? Admin fails on large content sizes. #3643

No response unfortunately... Maybe you could bump the issue.

Apart from the limitation, using pages that large is questionable though...

Yes, I agree on the page sizes being questionable, but these users are historians and there is much aversity against splitting things up. Having said that, Wikipedia seems to get away with lare text content per page as well, so it can work.

Thanks for the link. I bumped the issue. Hope that this time there will be an answer.

BTW, the workaround "B) Go into the admin panel, create your page, switch to expert mode, and save it, as it isn't affected by the restriction and the error does not appear" is not working anymore.

Okay, the commit you posted in the pull request helped me to solve this as it gave me insight how it works. You can actually change the limit in the blueprints. In my doc.yml blueprint I can add the following:

            content:
              type: textarea
              label: Inhoud
              rows: 20
              validate:
                max: 200000