Alas, this is really custom witchery and I don’t know if anyone’s successfully done it because that really isn’t how the software was intended to work.
CAN it be done? In theory. But you’re trailblazing :/
Just for reference I was able to get this working by setting the Site URL and Home Url to theirdomain.com/blog and then a mix of the output buffer and wordpress filters to catch all the urls that were incorrect so now i can successfully run frontend and admin from theirdomain.com/blog.
Even with domain mapping, WP really doesn’t like that…
Domain mapping would to “turn mydomain.com/username into theirdomain.com”
Why are you adding the subfolder?
Hi, the sub folder is because theirdomain.com points at our other system and its preferrable over a sub domain as we know for a fact nothing is at theirdomain.com/blog whereas they may have something like blog.their domain.com