You don't need a full 1:1 mirror of the strands, you can probably filter off a lot of the traffic that you don't need to spy on (e.g. TCP overhead) compress it and use a fraction of the bandwidth.
or Youtube streams...
That were my thoughts before, or at least how I'd do it:
- seal deals to get x strands
- tap it while still unlit
- mirror what you need and exfiltrate directly over your own private strands