Hm, if you don't actually need a sandbox then I think just using the C# run-time makes a lot of sense. I also like C#, but I've never been in a situation to try the fairly new AOT support. Sounds like a good idea, though. C# is a very good language.
DotNET: 0.061s
qemu-riscv64: 0.006s
Spike: 0.031s
Qemu is JIT with Linux syscall layer built in (in native code).
Spike is a RISC-V interpreter with Linux syscall layer provided by interpreted RISC-V "pk"
So the DotNET JIT has quite a high overhead for startup, or one-time code.
For very compute-intensive code DotNet has an advantage. e.g. on my own primes benchmark (https://hoult.org/primes.txt, https://hoult.org/primes.cs)
DotNET: 3.5s
qemu-riscv64: 10.2s
gcc: 9.7s (i.e. defaulting to -O0)
gcc -O1: 3.2s
DotNET beats emulated RISC-V here, but the RISC-V emulator (with RISC-V code compiled with -O1) is pretty much as fast as a lazy person compiling C to native x86 gets.
If you want to compare startup times you should be using .NET's AOT compilation so it doesn't need to load the full runtime or do any JIT compilation. See here: https://learn.microsoft.com/en-us/dotnet/core/deploying/nati...