The official uniswap v3 SDK unwraps the result using theunwrapWETH9 contract method.
The current behaviour is unexpected, since the output token is specified as ETH (address 0x0...0).
What's your position on this? I can probably make a patch that uses the multicall to swap and unwrap as I already have the code for it in my project. I think that for very least the uniswap-python should issue a warning log message at the moment.