I use both hit and exp(dodge) caps on my DK tank, for a few reasons.
Finally, Dodge DR is so ridiculous that by hitting these caps I barely lose any avoidance anyway.
but you are missing out on mastery or parry, which are both so much better than dodge. Though i do value hit>dodge because of the dodge DR combined with the fact that a RS miss causes a 1/5th cost RP drop meaning 8% miss = 1 less DS every 1.5ish mins. I also like the dps/disease application that hit provides
I've been playing with dodge scaling in my 3 plate tank and imo it should completley removed or revamp from the plate tanking gear.
It simple miles behind Parry(STR for hitpertise ppl).
Avoidance overally doesn't work well for DKs due the HUGE damage spike and it highley suggested to scrap every single mastery and stamina points you can get.
Because of the enormous HP pool i think DK should realize already how DS works and not spam it mindlessly.