The problem with Dakmor Salvage is that it's a judgement call between Dredging 4+ and Dredging 2 plus recurring X Bloodghasts and people have a hard time determining when/when not to Dredge 4+ or Dredge 2 and Landfall into Bloodghasts, not that Dakmor Salvage in and of itself is a bad card. That said I don't think Dakmor Salvage is worth it unless you're playing the full set because you're relying on capitalizing on as many Bloodghast activations as possible to justify it.
Where I think Bloodghast may belong is actually as 1 or 2x creature in combination with Ashen Ghoul, because you can recur your pseudo Ichorid and your Bloodghast off a single land without being "all in" on either strategy and adversely affected by Surgical Extraction, i.e. you SB in 4 Nether Shadow, 1 Bloodghast and 1 Ashen Ghoul. Another though I had was that Bloodghast may just be "over kill" and 4 Nether Shadow is all we really need to diversify vs. Surgical Extraction. If that's true, I actually think dedicating those SB slots, or more MD slots, to Dread Return and Dread Return targets may be the correct approach because a clever opponent can just Surgical Extraction Ichorid and Bridge from Below and leave you beating down with an army of flying and hasted 1/1s if he's clever :(
The reason I like Iona, Shield of Emeria and don't like Sun Titan is that Iona can either be a 7/7 flying pseudo-shroud vs Snapcaster control or she can serve the purpose of Flame Kin Zealot by getting you to your next turn, the kill turn, by disabling their win condition. The possibility that TES may be playing Silent Departure (which I doubt, because it's a fringe SB card with an unfriendly mana cost compared to Death Mark) isn't really a big deal, because if the opponent spends the card and mana resources to Burning Wish for Silent Departure then have to pass the turn and lose anyway.
Game 1 I don't think it matters whether or not you use Iona, Shield of Emeria or Sun Titan, but game 2 is where it matters because Sun Titan is only as good as your grave position (Dredge's version of board position if you will) and if the deck has suffered collateral damage from Surgical Extraction his end result is less than impressive where Iona, Shield of Emeria or Jin Gitaxis, Core Augor just "do what they do." I'm not even certain whether or not it's correct to MD a Dread Return target if we can SB it either, because the deck is just so lop sided game 1 vs everything we may as well cram 3 Careful Study in or play 4 Careful Study and 3 Breakthrough instead (I know Careful Study isn't as good as Breakthrough, but game 2 Breakthrough is more of a liability than Careful Study and SBing out 7 cards in LED and Breakthrough is actually relevent compared to SBing out 8. I really do wonder about Breakthrough in this deck, because the discard hand mechanic isn't that important with Phantasmagorian and the card is such a liability facing Leyline of the Void or Tormod's Crypt).
This is why optimizing Dredge is such a bitch, because it's hard to draw the line between just how broken you need to be to win game 1 and then knowing exactly how much of that you need to SB out for a resilient game 2/3 vs. hate. Maybe it's better to start from the "optimal" game 2/3 Dredge deck and work your way backwards to figure out what your MD should look like.
Regardless, I don't think these Surgical Extraction based SBs are going to really hold up vs. us. They don't seem to play anything but Surgical Extraction fwiw, so that means we pretty much still get to play with our draw spells game 2 and there's bound to be a way to punish that. I'm pretty sure SBing out LED is still the right call for Nether Shadow to bolster the ranks vs. Surgical Extraction and the extra MD space should probably just be devoted towards a 3 Dread Return/2 Reanimate Target package so we can free up some SB space for graveyard hate.
