I agree, that local editing of remote files would be better, but as you said, current options are pretty bad. Latency is still there, except it's in the filesystem level and file operations, rather than interaction with the editor itself.

I.e. both methods have their trade-offs. I find using remote nvim easier, even if you have to install and configure it first. At least if we are talking about some stable commonly used environment, and not about ad-hoc editing, in which case remote mounting might be a better option.