After saving my existing save with Factorissimo 3 and doing the migration with this mod, I got this error which didn't happen with notnotmelon's version:

The mod Quality Control (2.4.0) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event quality-control::on_configuration_changed
Error when running interface function factorissimo.is_factorissimo_surface: factorissimo-gadgetroch/script/remote-api.lua:156: attempt to index field 'surface_factories' (a nil value)
stack traceback:
factorissimo-gadgetroch/script/remote-api.lua:156: in function <factorissimo-gadgetroch/script/remote-api.lua:143>
stack traceback:
[C]: in function 'call'
quality-control/scripts/exclusions.lua:89: in function 'should_exclude_surface'
quality-control/control.lua:335: in function 'populate_excluded_surfaces_cache'
quality-control/control.lua:349: in function 'reinitialize_quality_control_storage'
quality-control/control.lua:437: in function <quality-control/control.lua:434>

Not sure if this is something that should be fixed by you or by the Quality Control dev, but I'm leaning towards you since it worked just fine with notnotmelon's version.

Thanks for the report, this one was on my side. Quality Control asks Factorissimo whether a surface is a factory floor during its own on_configuration_changed.

It declares an optional dependency on notnotmelon's version, which makes it load after it, but not on this one, so it ran before Factorissimo had initialized and the call crashed. 3.19.5 is out: the remote interface now answers safely at any point during loading. Just update and load your migrated save again, no other step needed.

This is better ?