Following discussions with Daniel and Jim, I've written some instructions in the CDS WIKI to manually ramp down any running excitation to zero prior to killing the excitation. This is only needed in cases where the normal ramp down does not result in a zero EXC input to the filter module (e.g. excitation filter with very long ramp down times).

https://lhocds.ligo-wa.caltech.edu/wiki/ManuallyRampDownExcitationPriorToStoppingExcitation

This procedure can be applied at any time during the measurement and does not need to be setup in advance.