Managed to load "Terminal" using your prescibed route. But after UsB is initialized in the box and trying to access the box using webif teminal, it keeps showing Error 404. URL not Found. So that is the end of road on that front for the time being at least.on the remote, press green, twice, choose extensions, scroll down to terminal and install it.
When you openwebif, Terminal is there
Reading in the "All Builds" section, it seems like that his problem has been reported and and in Grog's notice.