The magical part of Arduino isn't hardware with the Arduino branding, but a great set of open source core libraries & a easy to use toolchain.

This hardware unfortunately doesn't have either of that; it requires Intel Quartus for design and synthesis.

The Vidor is unusable garbage. Arduino's tools provide no support whatsoever for FPGA development on the board -- they haven't even clearly documented the process for uploading a new bitstream to the FPGA. For all intents and purposes, the FPGA is an expensive toy you can use to run their demo bitstream, and that's it.