I wondered whether, and if so how, a experimental time-resolution in treated. Is doesn't seems to be explicitly handled for now. However, somehow I expect that it is relevant: The decay scheme measured with a certain requirement that things are "prompt" will depend at least theoretically on whatever I define as prompt.
Have to look more in the code. There is a comment somewhere,
// no dipole or quadrupole decay option: effectively an isomer
which probably makes sense. They may get lifetimes much longer then what we would usually measure otherwise.