Since the official forum seems to be gone and I don't remember the URL to check it on Wayback Machine, I can't be 100% sure, but I'm pretty sure there were talks about open source and that people could write their own functionality for it. Maybe they just never went through with that.
IIRC, it runs Linux, so if you can manage to get shell access through a debugging port, root should also be possible (given that it likely uses an ancient Linux kernel I'm assuming there are exploits)
I'm guessing they would have had to have some sort of debugging port to use during testing, especially when testing new firmware updates before release, but there might not be test pads left for it on the board, and it's possible the firmware released to the public has debugging disabled.
If you could somehow have a look at the rootfs it might go a long way in figuring out how to interface with the FPGA. Either through shell access or by decrypting/decompressing the firmware update blob.