As a Roblox developer, it is currently too hard to utilise 64 bit numbers in Lua (or really any transformation of number that isn’t the native 2^53 for that matter).
It becomes more vital that we get this feature as Roblox evolves into a 64-bit client and we get numbers that start to encroach over that 2^53 threshold (also I’ve found uses for having 64 bit numbers on their own [looking at Int64 in the RBXM file spec]). Both Lua 5.3 onwards and JIT support this feature so why not Luau?
If you’re looking for an implementation, lets take a look at how C++ does it, C++ allows you to explicitly denote the size of an int using letter specifiers at the end of the number
For example:
0x100000000ULL would be an unsigned longlong (also known as a u64)
There are also quite a few things out there that depend upon having fixed length integers (signed and unsiged), such as encryption or randomisation algorithms (cough PCG cough).
If Roblox is able to address this issue, it would improve my development experience because I’d be able to utilise 64-bit integers inside libraries and Roblox as a whole