There's a new release of the LDAP module in the appstore, and this new release is Mx4 compatible and does not need the Mendix version specific jar-file anymore.
We are using an adapted version of the LDAP jar provided by Mendix that allows us to import to any entity and map all data from the user's CN. Maybe this can be made available for you too, as the standard version did and possibly (still) does not allow for this feature.If you're up to it you could start building your own version in java as well.
With regards to the version, we need to get a new version of the LDAP jar for every upgrade as there as some issues with the JVM on compiling the jar.
Hope this helps you a bit further.