If encrypted outputs can be viewed or used, they can be reverse-engineered through that same interface. FHE shifts the attack surface, it does not eliminate it.
Heads up: I left a Peerweb link open overnight (~8 hours) hoping it would load. It consumed ~15GB of memory and triggered an OOM kill, crashing the browser. Browser: LibreWolf (latest) OS: Fedora 43
I also had success, less negotiating, more just helping me form the letters in a few minutes rather than hours so I could get reimbursed for denied coverage, and it did get reimbursed.