do you think you could provide SASL binaries (saslpasswd2.exe at least, perhaps sasldblistusers2.exe and pluginviewer.exe) together with the svn command line tools?
Since client and server share the same registry keys, it's almost impossible to run svnserve and TSVN on the same machine while using SASL. If TSVN came with matching SASL executables, one could serve the repositories with TortoiseSVN\bin\svnserve.exe.
Kind regards