Their isn't anything we actually know to be fact regarding bans , nothing at all , it is 100% speculation. If they did know they would be able to write an undetectable firmware.
The LT firmware cannot be spoofed period. If you are using a benq you have to have a benq already in your 360 , the osig strings wouldn't match and you would get a DVD drive error at startup. If you just want to put a new drive in you can spoof with the older versions of firmware.
If you use LT you do have to have all security sectors correct if you want to be as safe as possible , it assumes you have everything correctly put on the disc. But we don't even know what they check so it really does not matter at all.
The bottom line is that there will never be a way to make a burned disc show up as a pressed disc , every burned disc has the information in different places , every pressed disc is exactly the same. They are always going to be able to detect this. Chances are the system does a firmware check at boot , if it has some other firmware than stock it flags you to be banned , that is just my speculation , but many people think other things.