We currently place our modules either directly to modules directory or to modules/system/layers/base. The info that every layered product should use its own layer directory under modules/system/layers/ comes from lkubik_jira who knows it from gvarsami@redhat.com. BTW, this means that current Keycloak is doing it wrong too.

This needs to be fixed in every Hawkular component which adds some Wildfly module. From the top of my head, this is at least Nest, Accounts, Agent and maybe also Inventory, and Metrics.