Message Pane visibility should be remembered per folder, as in Outlook. And should not be even visible for Spam, Junk, Virus and similar folders by default.
But WebExptensions API in Android version is incomplete. Extension developer can't add anything to context menus, as Menus API isn't implemented. Also composed pages appears empty.
This says Delivered, but there are still a lot of addons not working. Like Menus API not working at all. Nothing comes up in context menus. Start page dial addons not working, even with enabled Composed homepage.
Most spam is a fraud or malware. Unless you are a spammer you don't want to click links in spam or open files. Not to say of possibility of some vulnerability.
