"but the notification is just one" - it's expected. It starts a single workflow with multiple payloads by selecting a folder as a payload. There is no option to start multiple workflows for each asset in the payload folder.

Do you have a Dispatcher front end on those environments, where JSON call is failing? If yes, review the dispatcher rules and make sure that the call is nor denied.

If assets reside in the same folder, you can choose the folder itself as a payload destination.

Is it a Target via Adobe IO integration?If yes, you need to get to Experience Cloud Admin Console Admin Console From Product select Workspace -> Integration and add your Adobe IO integration with Approver product role

Try the following syntax:path=/content/mobile-appspath.self=falsetype=cq:PageContent1_group.1_property=jcr:title1_group.1_property.value=english asset1_group.2_property=root/videocomponentapi/text1_group.2_property.value=%english asset%1_group.1_property.operation=equal1_group.2_property.operation=l...

I don't think that having a large number of nodes' properties will be an issue.

OOTB "Resource Search Path Errors" is not configurable.  You can develop a custom Health check task to fit into tour business requirements: Operations Dashboard

You need to add two locations into a filter.xml:    <filter root="/conf/global/settings/workflow/models/mymodel"/>    <filter root="/var/workflow/models/mymodel"/>

I agreed with Yanira and just adding our official docs for the Health Check Topics:Operations Dashboard

There is no known limitation on the number of node's properties. For most of the use cases, you need to proactively index those properties that are used for a search.