I think an additional increase to the number of traps could be a buff to the trinket. Now whether that change makes sense, even I'm not so sure on. But when I commented on the number of traps, I wanted to speak on that which I felt was the main advantage to the trinket, as well as its weak point, in my opinion.
The trapped floors in earlier regions seem to have less traps than later regions. Maybe that's inaccurate and the later regions are simply bigger and the percentage remains. It seemed more sparse and later, denser.
This is one of the easier trinkets to level so I had it at +3 by the sewers. The floors that followed should've all had traps, aside from boss levels, if memory serves.
I prefer the getting the Geomancer since it can clear out the mine for me and save some time(hunger) having to mine, as well as find some of the rooms.
Once I spot it, I'll engage it right away. Clearing any mobs in the immediate vicinity first of course. If gnolls turn up during the fight, I'll take them out before reengaging. The geomancer's attack has a range so I'll lure any guards out of sight so the fight is easier.
But I don't bother clearing any rocks during the entire fight. Even with a sapper nearby. Typically, you can dodge either of his attacks, as well as the sapper's. Sometimes that's not the case. But I'll charge in and take the unlucky hits even without a backup, like chains or the hourglass. I play with 5 challenges and usually I'm not pressed for resources that I can spend the time to clear out rocks during the fight, but maybe taking a hit or two from the geomancer is an acceptable alternative. I think with more experience, you'll find the geomancer ain't so bad.
Be wary of standing by pitfall traps since the rock throw attacks can activate it.
I won't go down the dungeon if my armor is lacking. If I have mail+2 or better than I'm good to go. Maybe leather+3.