I don't know much about how Lift works, but would doing something akin to PJAX[1] (reloading the entire page via AJAX) work in your case?
With regards to state loss, the only way I can see it working is if you save everything to a system of reference, just like you'd do in Play. Unfortunately, that's also a major pain in the ass, as we've found out, especially in the case of multi-step forms in Play.
[1] http://pjax.heroku.com/