quicksync should let the i3 handle jellyfin just fine if you’re not going beyond 1080p for a couple of concurrent users. Especially if you configure the Nice values to prefer jellyfin over immich.

Most of my content is 4K h264. You may be right on the 1080 but I don’t have content at that resolution generally.

Worst case scenario he can always keep the N300 for other stuff if it doesn’t work out.