No.
404 is for “I can not confirm this resource exists”
For example, a private github repo must return 404 for unauthorized users, API requests must act as if that repository doesn’t exist (including returning 404 status codes).
403 is for “I can confirm this resource exists, you cannot access it”
There is no need, and you’re defeating the point of using tailscale. Use headscale if you cannot summit your anxiety around trusting tailscale.