Ben, finally I got the chance try to do it...
I was able go pass the problem you hit by setting the flag for "Knowledge Document Comments" to 1 using the pdm_load.
However, when I try to upload the rule in list_ntfr.htmpl I got server delay page as the stdlog showing error in
freeaccess.spl:
7556 ERROR freeaccess.spl 22350 AHD04646:do_checkout_with_timer::dob_by_persid(0) failed: Unknown name "0"
so the web engine does not allow this. As such, if you really want this happens, you may try to manually insert the rule
to the mentioned activity notification and see what happens. Thanks _Chi