The APM install needs to be curl-based just like the regular server agent. The manual steps can introduce errors. It also encourages admins to download the installer once and then use that for many months. It would be smarter for all agent installs to be command-line based like the server agent. That ensures the install is getting the most current version.
The removal process for APM should also be as simple as the server agent. This makes all installs and removals follow the same command-line process which makes all of our jobs easier.