AFAIK, every properly written VST plugin “links” to the correct channels. So in theory, you should never have to change the routing. Unless the number of channels don’t match. I just tried with Flux Verbsession, and all channels are correctly linked.
If you want to change the channel order anyway, you can use the Mixer Delay plugin, and insert that in the slot prior to the one where your plugin is.
HTH
Fredo