Shelly 3EM transformer calibration

Hi,

Is the calibration of the 3EM transformers specific to the combination of the individual transformer and 3EM device?

I recently had an electrician install two Shelly 3EMs on my house's mains and solar connections. I don't think she paid attention to which transformer came with which 3EM, so they got mixed around a bit. Do I need to recalibrate them? The instructions say "Use this option ONLY if you have to replace the current transformer with a new one", which isn't the case for me, but I imagine it probably applies anyway, in this case. And/or is there any easy way to work out which transformers were calibrated with which 3EM (so I can move them back to their original intended device)?

Also, the instructions I linked above don't mention anything about needing to have the transformers clamped to a wire when calibrating, but I imagine they both need to be clamped on the same wire during the calibration process, right? Does the voltage input need to be the same for them too (i.e. on the same phase), or is that irrelevant for calibration? How about neutral?

Thanks for your help and advice!

Thanks for your answer. It makes sense, but I wanted to double-check before getting it all ripped back out of the switchboard, re-calibrating it, and then installing it all again

I'm not sure how to work out which (if any) of the clamps are attached to their original Shelly. Perhaps I'll attach all six clamps to one cable and see if any of them manage to agree on a measurement. (And, if not, switch them all to the opposite device and then try again.)

How much inaccuracy would you expect to see from an incorrectly calibrated transformer? If it's only a few percent maybe I'll just live with it. And is it reasonable to assume that even an incorrectly calibrated transformer would still measure zero accurately?