I use iOS. I used my Impetuous Lootmonger to heist my opponent’s Dismember, but it would not let me pay life for the cost. I selected User Interface because it seemed to be a problem with the fact that it used the CMC “(3)” instead of “(1)(PB)(PB)” in the “Select Cost” menu, since it was heisted, meaning I couldn’t tap the mana pips to choose whether I would pay mana or life, since the Phyrexian mana pips were not there.