Anyone try to add TrueNAS to SRM or add any array not in the list?
Not supported in SRM. You should be able to enable SNMP and get some basic info by simply adding it as a node. If there are specific metrics you're looking for then I'd suggest using an Application Template (probably have to build one) that pulls in that data via API, custom scripts, or other means.
Application Templates are only available for [mention:de87ce885b14491598fc3011ec387ff2:23b05a61c3e5445190d9bfa00453bce4:label=Server%20%26amp%3B%20Application%20Monitor%20%28SAM%29] or [mention:a84e186fd01942edab9c43c038b14c6c:23b05a61c3e5445190d9bfa00453bce4] licensing.
Built a few custom ones in the past to answer the 2nd half of the question
We have SAM also. so SRM is not what is really needed in this case.