MongoDB - How important is the hidden property for an EBS snapshot backup secondary node?

Question

I have a Mongo replica set consisting of 3 nodes (1 primary, 2 secondary) running on separate AWS EC2s, using EBS.

One of the secondary nodes is a hidden dedicated backup db, and it's only task is to complete an EBS snapshot once per hour, which usually only takes 30-60 seconds to complete. It is set to hidden: 1, priority: 0. So the remainder of it's uptime feels wasted since it will not handle any read requests.

How important is the hidden: 1 property in this scenario, as I know Mongo recommends setting a db as hidden when it has a different workload like this? Is there risk of read requests performance dropping, or would read requests be sufficiently redirected to the other secondary whilst backup was occurring?

Also since the backup being taken is completed by the AWS EBS volume snapshot, would this alleviate any performance hit, since the Mongo EC2 instance will have the main workset in RAM?

Edit

Sorry, I should have made it more clear: Would it therefore be viable to make it visible, so that the backup db does infact handle read requests, whilst still continuing to do backups, since it is such a small period of time where the performance would drop?