I actually found a workaround for this too. For some reason if I use the format “Unit_X” (with an underscore — not Unit X or Unit-X) in the title field, then a search for Unit_30, for example, yields only Unit 30, not Units 3, 13, 23, etc. It requires a note on the directory page to the user to input the search exactly that way, but it works.
BTW, this software and template is exactly what I was looking for and thanks for taking the time to answer questions. Much appreciated!