See this discussion: https://moodle.org/mod/forum/discuss.php?d=74279#p728024 for implementing multiple servers. Does it add 1 more or can multiple servers be configured?
You can create a clone for each server that you need to connect to.
It would be a useful project to modify the architecture to enable arbitrary (and hence multiple) instances of authentication plugins. The need for multiple LDAP instances (in particular) comes up very regularly.
Indeed that would be great !!! i have to implement this solution too... in my case i have to plug a CAS authentication plugin with two LDAP server.