On the Linux desktop various apps would like to do lookups or modifications of anchor data via DBus. This also facilitates concepts such as privilege escalation (polkit prompting) to modify the system wide trust stores.
We need to look at the interested DBus callers and discuss the desired form. It is undesirable to design an API in a vacuum. Therefore if you are such an interested caller, please contact p11-glue@lists.freedesktop.org for discussion.