It appears that with conversion to clio this important bit of funcionality that allows us to balance lock counts on clients was lost.

Vitaly tracked it to this patch:

commit fd908da92ccd9aab4ffc3d2463301831260c0474
Author: huanghua <huanghua>
Date:   Thu Feb 7 08:07:16 2008 +0000

    b=14149
    i=yong.fan
    i=rahul.deshmukh
    i=nikita.danilov
    
    - use req_capsule interface for client.
    - add some interoperability support on server side.

The removal seems to be accidental.
Where before all enqueues came via a single path and ELC was alwas engaged, this is no longer the case.
The patch was cli_enqueue() -> ldlm_prep_enqueue_req()
and this call to ldlm_prep_enqueue_req() is now missing for glimpse enqueue.