Not sure anyone is still reading this thread, but I'll reply because I'm going to come back to it again someday.
Re http://svnbook.red-bean.com/en/1.8/svn.webdav.autoversioning.html (y'all need to do the rel=canonical stuff to get the /1.8/ out of your google search results). In that page, there is a mention of 'ModMimeUsePathInfo' that can add properties transparently. One like it could optionally add a sha1 as a property and that be transient like svn:log, svn:date and svn:author. Re the commands svn-ls and svn-info. They have an --xml flag already, and it would be cool if there was a way of adding select properties to that. Note that --xml and --show-item fight each other presently (and are singular). Of course best of all would be a GraphQL capability :-) - Paul