The uucp-1.04 that's in SLS 1.02 and later has all three modes of config files built in. While I can't test it, I did 'rtfm' and Ian Taylor tells me that it should work. If you use a 'Direct' device in the Devices file, there's now a 10 second timeout compiled in. Make the name of the Device anything other than 'Direct'. If you get chat script timeouts, typically connecting to other Taylor sites, a pause after login can fix this.
Some kernels experience modems hanging up after a couple of seconds.
If you want to do anon uucp in HDB mode, you'll have to recompile the sources with just HDB defined. Also, Taylor in HDB mode seems to be sensitive to white space and blank lines. To be safe, make sure that there are no blank lines or trailing spaces in the Permissions file. That tells which dialer to use in Dialers. If you had a ACU port, but none that matched the specified dialer on the same line in Systems, you'll get that message.