Who's responsible for this balancing!?
Maybe I don't understand how mining works since the rework, but unless I am mistaken, each swing is 4 game ticks (2.4 seconds) and this is what gives the XP drop. That would make the rate of obtaining clues while mining:
3600 / 2.4 / 2560 = 0.586 clues per hour (in reality less due to afk)
That seems way too low to make the perk worthwhile using.