Cannot filter audit by their audit_template_uuid

Isn't this already supported? Or are you referring to specifically the "id" field of AuditTemplate vs uuid?

stack@vm:~/devstack$ watcher audit-template-list
+--------------------------------------+--------------+
| UUID | Name |
+--------------------------------------+--------------+
| 8f1d6159-93ef-4cfb-b2bf-008f2b835380 | tdp_template |
stack@vm:~/devstack$
stack@vm:~/devstack$ watcher audit-list --audit-template 8f1d6159-93ef-4cfb-b2bf-008f2b835380
+--------------------------------------+---------+---------------------+-----------+
| UUID | Type | Audit Template Name | State |
+--------------------------------------+---------+---------------------+-----------+
| db14ac5e-f365-4987-8725-1c089a1b4b81 | ONESHOT | tdp_template | SUCCEEDED |
+--------------------------------------+---------+---------------------+-----------+
stack@vm:~/devstack$
stack@vm:~/devstack$ watcher audit-list --audit-template tdp_template
+--------------------------------------+---------+---------------------+-----------+
| UUID | Type | Audit Template Name | State |
+--------------------------------------+---------+---------------------+-----------+
| db14ac5e-f365-4987-8725-1c089a1b4b81 | ONESHOT | tdp_template | SUCCEEDED |
+--------------------------------------+---------+---------------------+-----------+

I can also use a query parameter of ?audit_template=foo to do the same thing via REST.

After redeploying another devstack I actually made it work. So I will put it as released