Well, if we are talking "technically" it's never silent assassin when you complete it casually, cause when we're talking "technically" we would be referring to the in-game calculated statistics and as Neonitiyo put it well, programming of the chair is the defining element of the Requiem's SA rating. Common sense is not the way of defining a run's qualities. That would be similar to saying that wallbang kills should not be accepted because there is a lying body on the ground, which has been eliminated by ballistic reasons and not an accident. But as the game's coding provides, that isn't a problem for the rating system, and it is perfectly fine. So, I think this category is perfectly fine and there are many improvements to do still.
Edit: shoutouts to Azekif with that 18 sec. any% run, damn its a great one
When I thought about that, I got what you mean by "legit". So yeah that's reasonable. I would go on with the default density settings on later runs as i discovered that each race has different density settings designed spesifically for it.
What is the policy for the traffic density? Because for example, in the WR video of Ignorance is Blitz, there seems to be 0 traffic density while in the WR video of Hold On Tight, there is some amount of traffic.
My suggestion would be the standart for speedruns should be 0 traffic density, because traffic leaves so much room for RNG rather than driving skills.