What I'm talking about is a hypothetical language that makes memory operations in critical sections forbidden and considered a compilation error.
Maybe it can answer to some parts of your reasoning? :/
This is easy to do in C, and you'll see it in embedded code. A simple preprocessor macro that redefined malloc to something that causes an error.
To enable malloc in some chunk of code (embedded defaults to "malloc is bad"), you can define it accordingly in the .c files that need it.
But Nim also has a new deterministic GC, that has been available since 2020 and will be the default in a future version, see: https://nim-lang.org/blog/2020/10/15/introduction-to-arc-orc...
In fact, I see many similarities between Nelua and Nim.
I am the Nelua author, and I've used Nim for a reasonable amount of time before creating Nelua, thus Nim served as one of the inspirations for the project and they share similarities. But while Nim resembles Python, Nelua resembles Lua. Also when comparing both, Nelua tries to be more minimal and generate more readable and compact C code.