I'm working on fixing the (many) references to changed prototype names in ATOM and it's associated mods, and I believe I've found a bug.

The item for the magnetising facility was fu_magnet_item and was changed to fu_magnet. So far so good.

The magnet material was fu_materials magnet... and also got changed to fu_magnet. So now items like the EM suspension train require 100 magnetising facilities to make - though you can use the 'cheap' recipe after the first one. So I don't think it actually locks you out of anything, but the balance is questionable.

Well that is a fun one to have missed. I will have to take the blame on that one as my pull request was added to the main branch and I missed that in testing

If that's the only one issue then you're probably not doing too bad.

I would ask, if you have any pity in your soul, change the item name of the building and not the material.

This is going to be an interesting problem to solve

Fixed or at least I hope so

Don't know if anyone else has brought this to your attention, but another issue has come up. Krastorio 2 has a function for switching roboports between a regular mode, a construction mode, and a logistic mode, with modified ranges; it does so by creating prototypes for each version and switching entities around. Since fi_robo_port changed names, the copies changed too, but since there were no migrations, any roboports that were in other modes disappeared.

Something similar might happen with Space Exploration and space-placable entities that SE makes space versions of, but not a lot of 248k buildings are space-placable to start with, so I don't know if any of them are actually an issue.