We have this issue as well and hope to eventually see another category such as "Non-Roman Script" or "Other".
Our current workaround is to sort by title (or contributor, subject or any other browse category) in descending order. That causes non-Roman script titles to sort to the top. Then you can page through the results to help find what you need.
Hope that helps, and if there are more elegant solutions, maybe someone will post here.
Kelley Canon