Dynamically changing conky network interface

I use conky on many of my machines, most desktop machines will have one or two network interfaces which I want to always monitor, but my laptop I often switch between many different network interfaces, (eth0, wlan0, usb0 and tun0), and I really like Conky's downspeedgraph and upspeedgraph. The issue is I dont want to be displaying all interfaces at all times. I only want to display the interfaces I am currently using.

I went to consult the Conky Doc (http://conky.sourceforge.net/variables.html) at first I came across:

${if_up <iface>} ${endif}

Which switches conky config blocks based on which interfaces are up.
This is great, but still always displays eth0 and wlan0 as long as the interfaces are enabled, even if they are not connected to anything.
Next I found:

${if_existing /sys/class/net/<iface>/operstate up} ${endif}

This will automatically switch blocks of your config only when an interface's "operstate" is "up". Surprisingly this is different from the ${if_up <iface>} statement and at least for me this produces the expected behavior.

I ended up using a combination of the ${if_up} and ${if_existing} mainly because for temporary interfaces such as usb0 and tun0 the ${if_up} statement works fine and looks cleaner.

Here is my current config:

Network ${hr}
${if_existing /sys/class/net/eth0/operstate up}
Down ${downspeed eth0} k/s ${alignr}Up ${upspeed eth0} k/s
${downspeedgraph eth0 25,100 dddddd ffffff 150} ${alignr}${upspeedgraph eth0 25,100 dddddd ffffff 18}
Total ${totaldown eth0} ${alignr}Total ${totalup eth0}
${endif}${if_existing /sys/class/net/wlan0/operstate up}
Down ${downspeed wlan0} k/s ${alignr}Up ${upspeed wlan0} k/s
${downspeedgraph wlan0 25,100 dddddd ffffff 150} ${alignr}${upspeedgraph wlan0 25,100 dddddd ffffff 18}
Total ${totaldown wlan0} ${alignr}Total ${totalup wlan0}
${endif}${if_up usb0}
Down ${downspeed usb0} k/s ${alignr}Up ${upspeed usb0} k/s
${downspeedgraph usb0 25,100 dddddd ffffff 150} ${alignr}${upspeedgraph usb0 25,100 dddddd ffffff 18}
Total ${totaldown usb0} ${alignr}Total ${totalup usb0}
${endif}${if_up tun0}
Down ${downspeed tun0} k/s ${alignr}Up ${upspeed tun0} k/s
${downspeedgraph tun0 25,100 dddddd ffffff 150} ${alignr}${upspeedgraph tun0 25,100 dddddd ffffff 18}
Total ${totaldown tun0} ${alignr}Total ${totalup tun0}