Hi Gambit, and thank you for your suggestion.
I think it makes a lot of sense, but it would add some complexity to the site for a feature that I don't think many would use, considering that there is a "how to write"section both in "words" and "kanji". This section already uses a different font, more close to what a regular handwriting should be.
Another workaround could be to install an extension like Tampermonkey and a custom script to replace the fonts of the site. I haven't tested this approach, but I think it could do exactly what you're asking without changing the user experience of the site.