Higher latency connections will certainly have longer delays, but it's quite fast on a reasonable connection thanks to the persistent WebSocket, even if you're sending each letter that's being typed. We're using Purview in production at the company I work at, and we haven't had issues with input-related delays.
If you don't need to send each letter, it's recommended to not do so; the submit event object includes all form data, so you can do one final validation at the end, similar to what you'd do with a normal web server.
If you don't need to send each letter, it's recommended to not do so; the submit event object includes all form data, so you can do one final validation at the end, similar to what you'd do with a normal web server.