You probably have missed the CH32V307, since it has been available for quite a while and does have a 10M Ethernet PHY. You'll probably need to have a look at its specs to know where the new CH32V317 comes from.
From what I've seen, it will have a 100M Ethernet PHY, but otherwise the same features, pretty much, including same amount of RAM and Flash.
I had found the base architecture here:
https://file1.elecfans.com/web2/M00/F9/B5/wKgZomaLiZSAbsi9AACqEawrpJw712.jpg(although I can't tell how authoritative this really is.)
The product still isn't listed on the official website, at least english version:
https://www.wch-ic.com/products/categories/47.html?pid=5#dataBut I just found a link to the chinese datasheet, which now includes the 317:
https://www.wch.cn/downloads/file/355.htmlI haven't bothered to automatically translate it, but from what I can see, it indeed seems to confirm that the main change is the 100M PHY, and I couldn't really see anything else different.
Again, the same with more RAM would be a winner. People have tended to find the 64K of RAM a bit tight for a TCP/IP library and typical applications, although it can be done. Note that RAM and Flash (for code) on this chip are related, and one can configure it for up to 128K of RAM, but then with only 192K of code Flash. That was the case for the 307 and everything looks like it will be identical for the 317.