Web Personalization Campaign error when text includes lead token?

We're experimenting more and more with Web Personalization (RTP), and I'm coming up against a problem of trying to create a personalization campaign for prospects on our home page.

It's a simple replacement of a span with a first name token:

Here's the simple replacement I've boiled it down to:

Any attempt at clicking "Save" or "Launch" ends up with an error upon click:

Anyone gotten this to work with a lead or company token in the replacement value? I've narrowed it down to any lead/company token, regardless of other values or special characters. Pretty sure this is a bug, just want to see if others have found it or there's a fix.

- Edward