Some info about the profil is here: Qlik Engine API ‒ Qlik Sense
change: [1,2] means that objects with handle 1 and 2 are invalid. 1 is usually the app.
If there is no Id in the package it means that it is not a reply but a notification. Is there another process working with the app? Perhaps a reload? That might explain 'suspend' that I have never seen before and seems undocumented.
Hope this helps
The part about notifications is actually in the jsonrpc spec, section 4.1 (it's not a long spec).
Note that a lot of fields, like handle, change, suspend (and also delta) are not covered by jsonrpc.