Depending on the content, you might want to consider adding tips to the help menu. Many or long messages you would need to scroll suggests, you want to provide some kind of written tutorial, Tips in the help menu might be the way to go. Tip notifications are also optional, players can turn them on in the help menu; this helps with not annoying experienced players.
If this is not about a tutorial or something, dialogs might be better suited
Hi: Is there a simple way to store messages into chat log? The action "text message" don't last long, and dialogs has no scrollbar.
As far as I know, no output from the game engine can go into the message logs, only chat message entered by players can.
If you want a good debug console, consider using dialog with a dialog item - list box. Scroll friendly
Depending on the content, you might want to consider adding tips to the help menu. Many or long messages you would need to scroll suggests, you want to provide some kind of written tutorial, Tips in the help menu might be the way to go. Tip notifications are also optional, players can turn them on in the help menu; this helps with not annoying experienced players.
If this is not about a tutorial or something, dialogs might be better suited