Please add package "pipe viewer" in next iso build. It can add progress bar and/or speed/transferred data size counters for any tools that works with pipes. Sure, dd with SIGUSR may be used instead, but it shows only size of copied data, only average transfer speed and have no idea about time to complete transfer.
Example (progress bar):
$ dd if=/dev/sda1 | nc ... &
$ while true; do killall -SIGUSR1 dd; sleep 30; done
1024+0 records in
1024+0 records out
1048576 bytes (1.0 MB) copied, 0.0053s, 19.7 MB/s
$ pv -t -p -e /dev/sda1 | nc ...
0:00:46 [================> ] 23% ETA 0:02:27