Theoretically speaking:Do events leave permenant & recoverable historical imprints on the spacetime substrate?

My answer to this question would be yes. But I would go even further and say that they do more than just leave permanent and recoverable historical imprints but that they never leave. All things in Universe are connected. The future is a direction correlation to the past so just by observing the present is evidence of the past and can be thought of that permanent and recoverable historical imprint.