Hi @joris,
Before being able to deliver to push the app to public stage, Ledger requires a web-wallet integration. The app is ready and fully working, and in consultation with the Zcash Foundation we decided to fork zec wallet because we had already a PR open with the current zec wallet that we would need to update, but we have already some previous knowledge on this. (See here PR)
Yes, YWallet is audited and actively developed, but we were not consulted on the submission of the proposal.