It's unfortunate but understandable that the stuff which is most different from other programming environments grabs attention and the basic stuff is hardly mentioned.
> break it irreversibly
Nope. "Cuis-Smalltalk records any action occurring in the environment: the code you edit in the System Browser, the code you execute in a Workspace. Therefore, in the event of a Cuis-Smalltalk crash you can restore unsaved changes when you launch the same Cuis-Smalltalk image again."
March 7, 1988 — "Smalltalk/V 286 is available now and costs $199.95, the company said. Registered users of Digitalk's Smalltalk/V can upgrade for $75 until June 1."
September 1991 — "Smalltalk/V code is portable between the Windows and the OS/2 versions. And the resulting application carries no runtime charges. All for just $499.95."
(Advert on the last page of "The Smalltalk Report")
== Long-ago, Smalltalk systems could be file-copied from say win to mac to unices and would just work.
== Not standardized. Language vendors used proprietary code to lock-in customers and that fragmented the skills base. Skilled Smalltalk-A programmers were not-so-skilled with Smalltalk-B.
Rust, Python, Java, Ruby, Scala, Swift to start with. These are languages with very wide adoption. Objective-C is very Smalltalk-like, but it is being phased out for Swift.
> break it irreversibly
Nope. "Cuis-Smalltalk records any action occurring in the environment: the code you edit in the System Browser, the code you execute in a Workspace. Therefore, in the event of a Cuis-Smalltalk crash you can restore unsaved changes when you launch the same Cuis-Smalltalk image again."
https://drcuis.github.io/TheCuisBook/The-Change-Log.html
> bespoke and unreproducible
So there have been all manner of ways to save code changes as plain text in files (or other formats in databases).
https://drcuis.github.io/TheCuisBook/The-Change-Set.html
https://drcuis.github.io/TheCuisBook/The-Package.html