e is using a very old PCRE library (7.6). While trying to build e linking dynamically to PCRE 7.9 I found that ucp.h no longer exists, digging through PCRE changelogs I found:
http://www.pcre.org/changelog.txt (Version 7.8 05-Sep-08)
"Replaced UCP searching code with optimized version as implemented for Ad Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-stage table and inline lookup instead of a function, giving speed ups of 2 to 5 times on some simple patterns that I tested. Permission was given to distribute the MultiStage2.py script that generates the tables (it's not in the tarball, but is in the Subversion repository)"
2 to 5 speed up sounds nice, I have no idea how difficult the ABI changes are to implement.