I am not sure that the current TT software (4/14/19 for 2018 tax year) actually treats my K-1 income this way, where it calculates my SE tax on the SE worksheet it is taking the full K-1 box 1 amount and entering it on line 2, it is not first subtracting UPE before calculating my tax. H&R block tax software appears to subtract UPE before the SE tax calculation aligning with your description and my understanding of how it should be calculated.
