Filesystem load to RAM vs piping

Still no joy. Should I expect a specific output before I disconnect the IDE? At the moment I get different responses depending on the baud but nothing readable.

USB.on('data', function(d) { Serial2.write(d); });
=undefined
Serial1.setConsole();þ
-> Serial1
Disconnected

or

=undefined
-> Serial1
ÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀ­ÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀÀ
Disconnected

By doing some mad and barely reproducible set of steps, including a baud rate of 4608000(!), I can occasionally get the flasher to connect

esptool.py v1.3
Connecting....
Running Cesanta flasher stub...
Flash params set to 0x0200
Writing 520192 @ 0x0... 120832 (23 %)
A fatal error occurred: Unexpected packet while writing:

but never to complete a write. I get different percentages of success but 23% is the highest so far.

I've ordered a new board because I'm pretty sure I've fried this one :(