Is it possible to run one of the umbrella apps in a different physical machine and still have the…

Interesting. I think in general you should try to avoid running an app on one machine that relies on code on another machine (in some cases it might be ok to rely on processes that run on another machine). I think the general approach for your case might be to deploy the umbrella and all the apps it contains to every server. At that point you could consider starting specific apps on specific servers. For example if you umbrella contains a “web” app and a “worker” app you could consider having the “web” app start on some servers and the “worker” app start on others but I think you’d need to deploy the entire umbrella to all servers. Interested to hear other opinions though.