Curious to understand if this particular glitch is still with us?

The particular issue is that the effect is indefinite, any re-spawned "enemy" is inflicted with the effect forever, including dragons.

Ha AWESOME!!!

Never knew bout this bug, sounds like a devilish thing to do

Never heard of this.

The only bugs I know of it, is that it conflicts with Drain Vitality and can make your followed weak if used on.

I'm not sure if respawned enemies still keep the effect of Marked For Death, but the rest of the bugs are definitely intact.

That is, the permanent and compounding reduction in armor, including pushing the AR into Negative values, which in turn multiplies the amount of damage the player does. It's possible to kill a Legendary Dragon in 1 attack with the "Fork" from Hearthfire after 3 or 4 Marked For Death shouts (TIII) Because you've reduced the target's armor to like -800.

More or less what i meant, yes.

Would it be so difficult to reset to default values, I don't get it?

Apparently this does not apply to an enemy getting an upgrade/downgrade when the 10/30 days respawn is up, as its a whole different value.