Nitter's author has suggested at least once that due to problems with Nim, a rewrite in Go is in the works:

"The long-term plan is to rewrite the source code in Go, as I'm no longer interested in using Nim. This isn't a small task, but building more features with the current state of things is painful. Before doing that I'll fix some feature parity issues, and work on some conveniences for instance operators. Stay tuned."

https://github.com/zedeus/nitter/discussions/1212