Setting up certs for inward facing services

Hey all,

Hope this is the right place to be asking (Reddit refugee), but do any of you setup certs for inward facing services? For example, I run "Whoogle" on my proxmox server, which I then access from several other devices when performing searches.

The connection between my machines and that proxmox VM are not encrypted, however only my VLAN (for personal devices) is able to access it.

Is it good practice to create a certificate for those types of servers that can only be accessed within your own network, or overkill?