Actually what I told you isn’t quite right. If you use empty, the CR based on that profile will remove things rather than ignoring them and the two CRs will fight. This would only work if you istioctl manifest generate YAML for the gateway only using empty profile and kubectl apply it yourself.
The easiest way to add another gateway it to add it to the main CR and keep it as the only CR. The operator watches the CR and applies any changes immediately. With this approach you don’t have to worry about potential conflicts between multiple CRs in the cluster.