Katrepid already happened in the Future Dimension, but it's not a given in the prime (that is a relative descriptor) dimension because the future is always being written.
The Nexus Force's understanding of Militiregnum is limited, so any inaccuracies I write are effectively reflective of that.
After the events of Talmid Show S3 E6 the Nexus Force was able to copy and build their own transporter technology based on the Talmidon's.