Our wildcard domain feature routes all matching subdomains to a single service, so it does not support dynamically forwarding different subdomain patterns (like web-myapp-pr-xx.mydomain.com) to different .up.railway.app targets based on the subdomain name. You're correct that it's designed for multi-tenancy where one service handles all wildcard traffic. To achieve the PR preview subdomain routing you described, you would need a reverse proxy or to add individual custom domains per PR environment, which could be automated via our public API.

Is this a feature railway would consider supporting in future without custom automations?

That sounds like a feature request! Can you write up a detailed explanation of your use case and the feature? This way other users can upvote your issue and glob onto it.

You can write your feature request and view the roadmap here ---> https://station.railway.com/roadmap

Thanks, created over at https://station.railway.com/feedback/allow-preview-environment-deploy-urls-to-dc244a3e

Thanks for creating the feature request! Others can upvote it there to help prioritize it.