[thaumasiotes]

Thanks!

Minor note: I was taught that forms of esse are weak enough that they lose their vowel to elision, so it would be de.co:.rust.

https://en.wikipedia.org/wiki/Prodelision

This seems like it would never matter for esse or est, but I guess it could preserve a long vowel in a case like -V: es V-.

[amelung]

Yes, de.co:.rust. Thanks for reminding me, I never knew or had completely forgotten.