Celebrim
Legend
Yes. The presence of damage on a miss is not an obstacle to my immersion in the game. It supports it, by reinforcing the key fiction around the PC in question - namely, a relentless dreadnought.
But its just lousy and creating that fiction. Nothing about 'relentless dreadnought' first causes me to think, "He does damage even on a miss." Moreover, 'relentless dreadnought' isn't even the color it's given by its own flavor and mechanics, which has nothing to do with being relentless and everything to do with simply hitting hard - so hard that even parried, blocked, or the blow fails to penetrate armor it still does damage.
(It's the fact that this mechanic gives no consideration to an active or passive 'dodge' that is creating all the problems.)
I'm not sure what 'relentless dreadnought' implies to you, but to me it doesn't imply 'never misses'. Maybe 'never stops', but certainly not 'never misses'. It more implies bounces attacks of its own armor, doesn't tire, impervious to fear, attacks ruthless ferocity, none of which immediately make me think, "doesn't miss". Rather, I think that you are coming to this from the other direction, "I have an attack that doesn't miss. What does it imply? How can I make this work."
And to the extent that it ever occurred to me to model 'relentless' as 'just keeps attacking', the concept would probably be more like the concept of Remise, which might have a mechanic like, "Once per round, if an attack misses you may reroll the attack applying a -3 penalty to hit.", or in my game a similar idea, "Once per round, if you missed an attack and you are not in an offensive fighting stance, you may shift to an offensive fighting stance and reroll the attack." Here the flavor is clear, "You missed but you simply won't yield the offensive." That's relentless. Damage on a miss is not even by flavor.