That’s actually incorrect, it is a solved problem in voyager. Clicking the link in the post from any Lemmy instance, or up to date piefed instance like piefed.blahaj.zone, opens in app.

The only reason it doesn’t work from piefed.ca is piefed.ca is running an outdated version of Piefed that doesn’t support the federated instances endpoint in api/alpha.

Proof:

https://piefed.ca/api/alpha/federated_instances

https://piefed.social/api/alpha/federated_instances