Hi @Chris1992,
Another option in this case would be create a script on your Synology storage which would run on schedule and report required parameters to Pulseway via REST API. If you will chose to use the REST API to monitor this instance, then you will be able to register it as separate system using REST API. For more details regarding the REST API for Pulseway, please check out the following link.
Let us know if you have any further questions regarding this.