"Brave" is far too kind. This is the kind of project nightmares are made of. Unless the pay was completely off the charts or I needed the work badly I wouldn't go anywhere near this type of project.
There was never any question of "can we actually do this?", just "can we do this in time?" Hence picking a tool that looked like it might offer some shortcuts. Yeah, it was a hell of a lot of work, but that was always going to be the case, and I accepted the project on those terms.
(My post perhaps came across as more extreme than the reality. We delivered. The site works. The code never got to 'unmanageable'. Given the opportunity to refactor this particular site, I'd leave it in Coffee, although I'd rework the build and deployment process.)