Glitch knew that taking the carriage to the front part of the outer region could be a little tricky, but he wanted to make it easier for Clifton to track him.
He knew that hiding from Clifton or that organization's eyes would not help him. It would only raise their suspicions toward him.
He also needed to spend a lot of time hiding his tracks, and he was not a fan of making things harder for himself.
It was much better to do everything in the open and just sneak in here and there when some necessary stuff came up. He was also not concerned about Clifton finding out about the letter or its content.
There could be two things.
First, Clifton could be part of this union, and it's just that Clifton was using another way to approach him, to hide himself in the background.