What does L2+ mean? I realize these aren't L3 switches with SVI capabilities, so what is the purpose of configuring static routes if there is no InterVLAN routing capability?
Welcome to Cisco Community!
With out getting into a huge discussion I will try to answer as quickly and directly as possible.
Our SFE and SGE series switches are Layer 3 switches (can also be configured as L2) so they are able to perform as a (inter VLAN) router or gateway for all VLANs. Once you have created the VLANs and assigned each an IP address, that IP address will become the GW for that VLAN. Under Routing you will not see any learned networks until you assign the VLAN to a port and the port becomes active. You will then need to configure a default route to send the traffic out to the cloud. The router will need to belong to the same VLAN as the switch. So if the switch has an IP address of 172.16.30.1/24, the router will have an IP of 172.16.30.254/24 for example. The route would read like this: 0.0.0.0/0 next hop 172.16.30.254 metric 2 (or higher).
As for static routes as a L2 or L3 switch, they would be useful when you have a device attached to another switch which is disjoined from your typical network on the local switch. In other words, lets say you have 3 (aside from default native VLAN 1) VLANs V10 - 30. All you of your devices belong to these VLANs but you have a server on VLAN 30 which is not connected to this switch. You will then create a static route for that server's IP address to the remote switch.
VLAN30: 172.16.30.1 (local SGE)
Server: 172.16.30.200 (on remote switch)
Remote Switch: 192.168.20.1 (remote SGE)
VLAN30: 172.16.30.2 (on remote SGE)
destination 172.16.30.200 next hop 172.16.30.2 metric 2
I hope this answers your question. These are really my favorite switches, as I find them very reliable and highly configurable. I love these things.