This is the way! Also without having to open a port, you can use dns over tls. Also use duckdns or any other free dynamic dns provider.

Would you mind sharing your process in a write up?

I think it really depends on which version of photoshop you are trying to run. Older versions should run better afaik. I’m not sure the current version even runs with all the cloud dependencies. You probably just need to try it out and compare directly. I moved my photo editing to photopea so I can’t really tell you more.