My goalposts are in precisely the place they started: a collection of basic international gestures to facilitate the most basic communication. Where are you jumping to colonization? Where did I say that my cultural group gets to decide what the signs are? You’re, again, wildly overestimating the scope of my proposal and jumping to ridiculous, unsubstantiated conclusions.
You get a group of signers from around the world to develop an international pidgin (like they already do informally at international gatherings) and come to consensus based on commonality. When the majority agree on a sign, use it. Where there’s little agreement, choose a new sign. No finger spelling, no complex abstract concepts, just a formalization of gestures most people could probably figure out anyway. I fail to see how that perpetuates colonization unless that’s what you’re setting out to do with your methodology.