I would take one more before SN, if i don't feel side effects. But you have to take into account how you feel. Meto is a dopamine blocker and dopamine is a neuro transmitter. Neurological side effects can be, for example. shaking, panic attack. If you feel strong side effects you have to choose other anti emetic!
PPBook:
"An alternative form of administration to take the drug for 48 continuous hours prior to the planned death at the usual 1 tablet (10mg) every 8 hours (ie 3x per day)
Note: this regime removes the need to synchronise the taking of the metoclopramide with the taking the lethal drug. It also serves to uncover any possible adverse effect of the drug leaving time enough to seek an alternative, if neccessery."
Like this: (she took 40mg at the same time)
https://sanctioned-suicide.net/threads/i-had-an-allergic-reaction-to-meto.13258/#post-264224