Thank you for noticing it! I thought iD must take care about it, but it doesn't. Fixed!

Seems you're talking about some other changeset. During my edit I just deleted 4 nodes from the way and it is clearly visible from the changeset

Could you please gave a look at my changes https://osmcha.org/changesets/148069462 and your changes https://osmcha.org/changesets/148069883 of this building and show me where did you find 7.5 meters?

And you successfully restored "too many nodes" I've deleted.

Could you please specify the maximum "distortinon" of the building shape in meters I've made?

I reverted the change and checked, seems I didn't move anything

Oh, sorry! Didn't know!

Oh yes! I'm usually doing it! But this changes were made in Vespucci infield, so I didn't close the edits and planned to change street tags next morning from home :-)

Railways you created are completely destroyed now: constructions sites are there. Is there any reason to store these historical data on the map?