ImmediateAcknowledgeAmqpException lost due to globalErrorChannelCustomizer bean.

Describe the issue
When handling a message from errorChannel and throwing ImmediateAcknowledgeAmqpException so that event is not placed in dlq, this exception is being lost because the following bean configuration:

@Bean
	public static BeanPostProcessor globalErrorChannelCustomizer() {
		return new BeanPostProcessor() {
			@Override
			public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
				if ("errorChannel".equals(beanName)) {
					((PublishSubscribeChannel) bean).setIgnoreFailures(true);
				}
				return bean;
			}
		};
	}

is forcing to ignore failures. Hence ImmediateAcknowledgeAmqpException is not being propagated correctly and message remains in Rabbit dlq.

It was mentioned as a temporary solution: https://github.com/spring-cloud/spring-cloud-stream/issues/2066#issuecomment-766820249 to fetch the bean from applicationContext and override the bean's property. This temporary solution worked.

Suggestion
However, is it possible to improve the temporary solution by having @ConditionalOnProperty annotation on the bean for example?

1. ServiceActivator

@ServiceActivator(inputChannel = "errorChannel")
public void error(MessagingException exception) {

    if (removeMessageFromDlq(exception)) {
        throw new ImmediateAcknowledgeAmqpException(exception);
    }
    log.info("Keeping message in dlq: {}", exception.toString());
}

2. spring-integration method handling exception in BroadcastingDispatcher class:

private boolean invokeHandler(MessageHandler handler, Message<?> message) {
        try {
            handler.handleMessage(message);
            return true;
        } catch (RuntimeException var4) {
            if (!this.ignoreFailures) {
                if (var4 instanceof MessagingException && ((MessagingException)var4).getFailedMessage() == null) {
                    throw new MessagingException(message, "Failed to handle Message", var4);
                } else {
                    throw var4;
                }
            } else {
                if (this.logger.isWarnEnabled()) {
                    this.logger.warn("Suppressing Exception since 'ignoreFailures' is set to TRUE.", var4);
                }
                return false;
            }
        }
    }

Please note I did try setting spring.integration.channels.error.ignoreFailures: false which didn't make a difference.

Version of the framework
spring-cloud-stream:3.2.4
spring-cloud-stream-binder-rabbit:3.2.4
spring-integration-core:5.5.16

Start with the globalErrorChannelCustomizer BeanPostProcessor and BroadcastingDispatcher.invokeHandler shown in the issue, then trace how errorChannel and ImmediateAcknowledgeAmqpException interact. Check why the spring.integration.channels.error.ignoreFailures setting has no effect. Done means the exception propagates correctly without the applicationContext override and the Rabbit DLQ behavior is covered by a regression test.