I think you've not witnessed Ship of Theseus, but "build Ship2 next to Ship1 and start using Ship2 while Ship1 is still being used and keep saying you're going to migrate to Ship2 eventually but meanwhile Ship1 and Ship2 diverge and now you have 2 ships".

I recently witnessed this mess and it is an enormous mess. Don't build Ship2 in the first place. Instead, replace Ship1's mast and sails, and rudder etc until you've replaced all the parts in Ship1. That's the SoT approach.