I know you have good intention with that post, however i also listened their video and the "repair" they do is replacing deffective module from a serie inside the cell. The problem is that you have to get very well matched cells the same age , capacity and internal resistance to get long term good result.
They actually dont rebuild pack with new cells It is WAY TOO MUCG COMPLICATED and would cost million dollars in investment to get spotwelding machine, ultra ssonic welder and have acces to the fresh cells and maybe print with 3D printer some cell holder they would have scanned with some 3D lidar camera... etc
I talked to Mr Gruber himself about the last video of the authopsy of a Tesla Roadster battery slice and the cells are all glued with epoxy to the holder ... = nearly impossible operation to get bad cells out and replace them with teh matched cells.
I myself repair various lithium battery since 15 years now and the most difficult part is not find the problem.. it is to find cells that match the exact characteristics of the rest of the cells that are still good inside the pack.
It is possible to just swap deffective cells or cell modules.. however the "succes" wont last long aks the unbalance between the older cells and the new replaced cells will get more and more important and eventually the weakest link in the serie of cells willmake that battery with very low capacity
I like Gruber motor as they explain very well at a great rate everybody can easy understand, but a truely repaired pack that last long will not appear in the coming years in their garage i think.
Doc