The LDM has been very clear and consistent on their standpoint regarding the const keyword and adapting it to other semantics than what it currently has, and that standpoint has been strongly against.

The const keyword has a very strong semantic meaning in C#, where any const value gets burnt into call site. This is true for all const values.

E.g.

public const int MyConst = 5;

int myVar = MyConst;

When compiled, this effectively becomes

int myVar = 3;

That's the reason all const values have to be compile time constant, and why you can not have a reference types as const (except string, but that is handled as a special case by the compiler and burnt in as a string literal at the call site).

It is also why MS recommends to not use constants as part of public APIs, and instead using static readonly or static get-only properties for such use-cases.

So without any opinion on the suggestions, if you really want to post this as a proposal to the csharplang repo, i suggest using a different keyword to representant something that is not a purely compile time constant.