Recovering a LiFePO4 cell (A123) at 0V

I have a V1 Boosted Board with a broken battery.
Some of the cells have discharged down to 0V and I wanted to ping the experts here on approaching cell revival before I start trying to rebuild the pack.

( unfortunately, due to utterly and stunningly incompetent design by Boosted, leaving the board unattended for a few months will cause the packs to discharge to complete zero )

Can a LiFePO4 cell be recovered from 0V?
I applied a constant current power supply to one of the cells at 0V by tapping into its ends directly in the exposed pack, and at 400mA the PSU was only developing ~0.7V to drive that current. Leaving it for several hours did not yield a voltage increase.

Is this a sign that the cell is dead?
Should I expect it to take a higher current pulse to begin the revival?

A cell that's gone to zero is permanently damaged. It's possible that LiFePO4 isn't as dangerous after this as other Li chemistries, but they may be unsafe to use.

With other types, there have been spontaneous fires/etc. with cells that have discharged to zero and then been reused anyway. I once did reuse an EIG NMC 3s1p 20Ah pack that was discharged to zero, and I very slowly trickle charged it at a few mA, then a few dozen mA, etc., until it was back up to "normal" voltages, but I did this outside with containment in case of fire. The pack continued to function reasonably well considering, but eventually died with a puffed cell in a different incident...but I didn't ever fully trust it, and it was only used for low-current lighting power.

But if you do want to recharge them, do it at a VERY low current, keeping in mind it can sometimes take many hours to bring them to their "LVC" point, at which you could then begin to charge them at a little higher current.

Until they've been fully charged at least once, at the lower current, and tested to see if they still "work", I wouldn't charge them at normal / high currents.

Any cell containing a Graphite electrode as anode (LFP is the cathode) may start forming metal lithium dendrites (needle shape structures) in its surface when discharged to 0 volts. The lithium dendrites will only get bigger and bigger as you try to cycle such cell, until at some point those dendrites will puncture the separator(the internal layer preventing the cell short-circuit) and produce a short circuit. If such event happens close to the fully charged state, the cell may explode. TLDR: A lithium ion cell which has reach 0 volts may be damaged and you should not attempt to bring it back to life.

I tried recovering some Lifepo4 cells from a Segway pack that had self-discharged to 0V with no success what so ever. Dead as a door nail. Wasn't so much interested in re-using them as I was in testing to make sure that the BMS would function with new cells.

i've tried to revive many a cell at various voltages, mainly cobalt oxide lithiums ( older chemistry), if I catch a cell before it gets below about 2.5v there is hope for the cell, anything below that and the capacity will likely be low.
I've tried reviving lots of cells below 1volt, and there is great variety in the cells responses.
If the cell wont hold any charge after puting on a low current for a while ( just 5 mins is enough), once charge is stopped if the voltage drops backs to zero, then you can give up on that cell, it will never hold charge, probably some sort of a short in it.
If the voltage rises and it holds some voltage then its worth continuing ( even if just to see what happens), but my experience is
even if you can get a cell thats been below 1 volt to come back up to normal charge voltages its capacity will be greatly reduced and probably not of much use.
I've found the low current is best way to go.