One of the original goals of the "pure-data" common source code repository was to be able to easily find Pd code. I think that now that there is a lot more development activity, I think that this no longer makes sense as a technique for cataloging code. I think that a wiki page on puredata.info would make a lot more sense, or perhaps other things.
Now people are starting to use svn:externals. I support the goal of findability; I do not think that svn:externals is the best way to do that. I think svn:externals is a tool for very specific cases. The pdmtl svn:externals was already causing problems because it uses a non-official TLS cert. This can break autobuilds, for example, and cause lots of headaches and support requests. I don't know of any other project that uses svn with svn:externals as a method for cataloging code.
So before we fill up the pure-data SVN with svn:externals links, I think we should make it clear what they are good for.
.hc
------------------------------------------------------------------------ ----
Access to computers should be unlimited and total. - the hacker ethic