> The transistors cannot simply be replaced. Clipper’s aluminum-zinc electronics vault, meant to provide a measure of radiation resistance, was sealed in October 2023.

Surely they can be replaced! Humans (in cleanrooms) can put their hands inches away from them. Here's a picture, admittedly from 2022, before it was sealed:

https://europa.nasa.gov/resources/342/electronics-vault/

It's not the same as saying they've failed and are in orbit around Jupiter and so can't be replaced. They simply need to open and re-seal the vault or build and seal a new electronics vault before October.