I wish there were some option to disable upgrade until the post-upgrade production of a unit type would be at least equal to the pre-upgrade production.
The double arrows at the dialogue imply that they advance to the end of the dialogue, not simply the next sentence of it. Someone who wants to read the text would only click the double arrows out of lack of any other options to advance.
I've gathered that the algebra-looking string of characters seems to refer to tool durability, but it does a very poor job in giving useful information to the player.
 "Incremental Cubes")
 "Underworld Idle")
 "Dream World"){kind=icon}
 "Knight-errant")
 "Storm Wars")
 "Deck Adventures - Origins")
 "The Town with Only You and Me")
 "Overlord's New Mansion")
 "Milky Way Idle")
 "Paper Knight Quest -The Cube World-")
 "Worldgence"){kind=icon}
 "Shoot & Sow")
messaged you for more information