

What’s your throughput to another Windows box from your source machine? Samba isn’t known as a fast transfer protocol. You could also try NFS services on the windows box and export your shares to try that.
You might also enable jumbo frames if it’s a lot of larger files.
Man, I was excited about Technitium, but I’ve had a hell of a time trying to get it to work. I’m not sure if it’s intended to be on a DMZ in order to get TLS working or something, but I’ve not been able to get it to acknowledge a single DNS request, even when I think I’ve shut down DNSSec entirely.