I'm pretty sure this is wrong...

MicroProfileMetricsSubsystemAdd installs DUPs but the MicroProfileMetricsSubsystemDefinition uses ServiceRemoveStepHandler as the remove handler. But that handler doesn't (and can't) remove those DUPs.

This is minor because the description of the remove op is ok:

[standalone@localhost:9990 subsystem=microprofile-metrics-smallrye] :read-operation-description(name=remove)
{
    "outcome" => "success",
    "result" => {
        "operation-name" => "remove",
        "description" => "Remove the subsystem",
        "request-properties" => {},
        "reply-properties" => {},
        "read-only" => false,
        "restart-required" => "all-services",
        "runtime-only" => false
    }
}

It says '"restart-required" => "all-services"', which means this can be fixed with no change to the reported API.

I think this should use ReloadRequiredRemoveStepHandler.