If anyone had, I'm sure I would know about it. Humax have never made such information public, and multi-layer circuit boards populated with surface-mount narrow pitch components are notoriously difficult to reverse engineer. It would be possible, with enough motivation and a willingness to destroy one in the process.
Most of the complexity is buried inside a system-on-chip, with hardware modules dedicated to the specific functions required such as video stream decoding, encryption/decryption, HDMI interface, networking, etc. The internal operation of the SoC is invisible from the external connections.
You may think this 'sad', but living in my own, this forum in particular provides one of my main forms of social interaction. That doesn't mean I'm not busy (sometimes more than others) and need to make value judgements for time spent.
General strategy: answer in brief initially, then provide full commentary later if warranted. Some of my input takes hours to compose, or even days, and while I had that sort of time under previous circumstances I now have to make serious choices where the effort is justified.