A compelling post. Something it doesn't mention that I immediately wonder about is how you ensure the decision to escalate from "a quick DM" to a "full business case review" (or whatever) isn't unreasonably biased.
If everyone is working with good intent then this doesn't matter. But the real world is full of unconscious 'isms so I suspect there's a risk that underrepresented folks are more likely to trip the extra process flag and thereby get slowed down disproportionately, leading to negative feedback loops.
That's a really good question. This may also end up depending on the level of trust within the team. One thing I didn't call out is that an "optional gate" can still just be checked by sending a DM, like "Hey, do you think I need this check on this project?" So in high trust teams the differences are small.
On lower trust teams, I could see the cycle you mention crop up more. I'm not sure of the answer, but I don't think it is to force everybody through the onerous process out of perceived fairness. Any ideas on how to bring visibility to that failure mode?