The shorter duration is also more common with lower dose IV infusions. There is evidence that higher concentrations (usually delivered infra-muscularly or sublingually), and the k-hole experience OP describes delivers more long lasting results. In the Ketamine Assisted Psychotherapy space, there is a lot of criticism of the infusion model of a nurse managing simultaneous infusions on several patients at sub-psychedelic doses as a cash treadmill, as opposed to a deeper psychedelic experience which can be more costly to deliver because ideally it demands pre and post integration plus administering to a group can be problematic if someone experiences a “bad trip”. With some preparation and screening a lot of the doses in a series can be managed at home though.