We've already tested it (including the VC map), and, while I think it would be awesome to make a new VC map for PTP, I don't think opening a test server is a good idea right now. First of all, it would split our (already small) playerbase, I could see a lot of regulars going there, leaving this server pretty much empty and thus not attracting more new people on this version, while this is still the most popular version right now. Yes, it could attract some more people playing on 0.3DL, but I don't think it could account for the players we'd be losing here.
The second issue we noticed while testing 0.3DL were the download speeds. If we want to have a VC map, everyone joining the server would have to download all of the custom objects used in it. I don't know if this has improved in the meanwhile, but it took some time to download, which could add an extra barrier when new players are joining the server, and could lead to them losing interest.
So, I think it would be better to just stay on 0.3.7 for now, and only switch when 0.3DL becomes part of the main SAMP branch.