If you cannot think of a solution to solve a simple problem of a handful of people not "validating" their keys and are prepared to delay an entire operation as a result, what hope is there when there is a significant problem to deal with?

Again send emails until the 11th and fire away.

100% this is not the problem. How was it determined to wait till the end of the month + maybe into May to wait for these remaining people exactly? How exactly is this delay determined? In particular the 'maybe into May' part? Was a survey done? Did emails get sent to those people and they replied and begged please wait I am on vacation, I am in the hospital?

Bullshit.  This delay and maybe into May is something else. Not waiting on people to validate their stupid keys.

Prove this wrong by sending everyone an email each day until the 11th, failure to respond, send their funds back to their sending address. Or proceed minus them and include them later on.