Tag replica set nodes without election or reconnections

I'd like to add tags to existing nodes in our replica sets (mostly to identify the Amazon Availability Zone), but it looks like the easiest way to do that is to modify the config and run rs.reconfig(cfg). Since running rs.reconfig() has the potential to trigger an election, it would be fantastic to have a way to modify tags for replica set nodes without the chance of an election or the nodes dropping existing connections.