Any digital circuit can be made reversible using components like the Fredkin and Toffoli gates. This includes SHA-256. As much fun as it would be, there is no fundamental need to develop a new algorithm for the Bitcoin PoW. It would truly be interesting to engineer a reversible SHA-256 computing device and see how it compares in speed vs. energy consumption against the current generation of non-reversible ASICs. In practice only the hottest portions of the circuit benefit from being made reversible. A hybrid circuit of both reversible and non-reversible sections is likely to be the one that gives the best trade-off of speed and efficiency.
yeah but if they are using private chip like for example in the baikal miners, you can-t get anything out of reverse engineering which is the same as recersible computer to me, you can build the board and anything but the chip is what matter