I. Dunnow, witholding the plan from anyone aboard the rebel ships seems silly when the alternative in peoples minds is 'we're running until out of fuel, and then we shall die'. That kind of prospect would encourage damn-fool behavior.
Given that technology-based external tracking through hyperspace was long thought to be impossible (and is one of the party tricks of the Supremacy), it's completely reasonable that they had some kind of First Order spy on board and needed to keep their strategy hidden. I really didn't think they needed to spoonfeed that to the audience, given that, "You can't track through hyperspace without some kind of active homing beacon planted on the target" has been a major plot point in multiple previous Star Wars movies, all the way back to A New Hope itself.
But, that aside, the dreadnought getting blown isn't shown to be as negative as it maybe should be? When they get into that chase sequence, Poe being wrong gets argued against because now at least the new-Imps don't have the big-ass laser cannons with them that would presumably be quite a problem for the shields.
They're not big-ass laser cannons, they're orbit-to-surface autocannons with no ship to ship capability. Dameron was just being target fixated, much like WWII Japanese aviators who always went for the most glorious target.