Cloud Gateway Fiber as Wireguard client?

I have a very ignorant question about networking and DNS:

I have access to an external Wireguard service I'd like to use for networking some of my devices. I know it's *possible*, but Synology makes it very annoying to put Wireguard on a Synology NAS. If I wanted to use this Wireguard server (as opposed to, say, Tailscale) I was wondering what my options are for connecting to my NAS when outside of the house. I know I could just host Wireguard on my Cloud Gateway Fiber and just connect directly into my home network via that, but I was also wondering:

What happens if I make the Cloud Gateway Fiber a *client* of the external Wireguard server (say my home network is 10.1.1.* and the VPN is 10.2.2.*). Is there some way to route traffic via the CGF such that my laptop, out of the house and now another client on the external VPN 10.2.2.* network, can reach a NAS (by, say, SMB) on the CGF home network, say, 10.1.1.100? Or there isn't a good or easy way to route traffic as such across those networks, when the CGF is a Wireguard client?

Or, what are other reasons people would use their CGF as a WG client and not server?

(Thanks in advance, sorry if this is a silly question!)