34 Button 26 DIY2 13 4F 00 FF B0 4F
35 Button 27 DIY3 14 8F 00 FF 70 8F
First of all, I don't know what is OBC. Please expand abbreviations the first time around.

Taking just these 2 examples, it seems pretty intuitive to me.

Let us take the case of Sigkey#34 button 26. The code you see is 00 FF B0 4F
The first byte 00 must be some kind of device ID or something.
The second byte is just the binary inverse (NOT operation) of the first byte
The third byte is the function code
and the 4th byte is the inverted function code. Just like the second byte.

The easiest way to do this is to have a lookup table having the codes for bytes 1 and 3 and you generate the bytes 2 and 4 before sending them out.

It's that easy