(Edited to remove less interesting solutions)

• Harry can tell Voldemort that Harry's death has an unknown chance of hijacking Voldemort's horcrux network, and neither of them have enough information to push that probability below 5%. As far as I can tell, that's simply true. We know that Voldemort hasn't done any tests of the improved horcrux spell until now, and has been mistaken before about its working. The Voldemort described in this chapter would not accept a 5% risk on this particular plan, so he will carry out some experimental tests before killing Harry. That seems to allow Harry to evade immediate death, which is what Eliezer asked for.

• Harry's death burst will very likely interact with Voldemort's magic anyway, like the wards Voldemort placed around the spot, or the dark marks on minions' hands. That changes the whole plan. Now Voldemort must get himself and the minions far away at the moment of Harry's death, and also lift the wards. That buys some time as well, and is compatible with the previous idea.

• Voldemort has just taught Harry how to un-transfigure stuff wandlessly. If Harry's glasses are some sort of transfigured distraction that could be used to buy a couple seconds, Harry could use it, and immediately fire Flitwick's swerving hex. I'm pretty sure Voldemort doesn't know about that one, can't dodge because the hex was fast enough to drop Moody, and can't shield because that would count as magic touching. (Moreover, even if Voldemort dodges, the hex might still touch his wards around the graveyard, so maybe Harry can just fire in a random direction.) That could be one way to cause a resonance cascade, what happens next is anyone's guess.

ETA: I just posted a more fleshed out solution on /r/hpmor. It's very likely that it can be improved even further.