This was a location that allowed both parties in a trade to lower their guard somewhat.
But if he were to approach as a "righteous and kind" Silver Dragon, it wasn't just a matter of whether the other party would flee at first sight. Instead, dark creatures from over half the Gloomy Region might be stirred to action by the news and unite to attack him. As for those perpetually insatiable daughters of Spider Nest City, they would likely fall into a collective frenzy. No matter the cost, they would abduct this "Silver Dragon," forcibly accelerate its growth, and then use it for breeding.
The High Elves might still be wary of the threat from Dragon Island; after all, they were a prominent surface power and had to consider their reputation and business relationships.
But what were the Drow? Calling them street rats would be an understatement.