I am working with ldap features of liferay since last one year. But to do any change in LDAP Import or Export logic we have to do change in the EXT Part. And as you know it is very time consuming.
It would be better if LDAP is moved to Service layer or plugins part.
And also the CPU Usage is one of the biggest issue, we are facing with the LDAP + Liferay Integration.
While importing users near about 10k, it was consuming CPU Usage near about 98 to 99 %.