Let me take this one, and also briefly introduce myself. I am Borys Wróbel, Nectome’s chief scientist.
In principle, crosslinking with aldehydes is a reversible reaction. Strictly speaking, a bunch of reactions, all reversible, is involved. But “reverting” the process of fixation at the level of cells and above (organs, whole organisms) in the sense of bringing these biological entities back to biological life is likely to require a similar level of technology as nanotechnology required to “revert” the damage caused by current cryonics practices. In particular, “traditional cryonics” after short postmortem intervals leads to severe brain dehydration “undesirable because of mechanical distortion and toxic effects of concentrated salts”. This is a direct quote from the paper I co-authored—the main credit goes to Andy McKenzie though—https://www.mdpi.com/2076-3425/14/9/942, which also discusses briefly the issue or reversibility.
Hi, the main discussion we had was about the physician-assisted death in Europe vs US. PAD allows for the preservation to be a planned procedure. At first the legal/cultural situation in Europe (specifically, the Netherlands, Belgium or Spain) looked better. But then when we actually investigated it in more detail—and I spent almost 3 years on this...End result: we decided to concentrate our efforts in the US, specifically in Washington and Oregon. This does not mean that it can’t be done in the EU now or in the future. It just makes more sense to start here.