It's not really important whether the text is visible, you can just put the instructions in the middle of a long document, or use a low contrast color, or a small font size, or any other of the myriad of ways to make text hard to read.
I haven't seen data that would confirm that the Nim ARC/ORC approach is faster than manual memory management (C/Rust/Zig/...) on programs with non-trivial lifetimes (for trivial lifetimes, Nim elides RC). I'd also be somewhat surprised if it was consistently faster than GC – most languages with automatic memory management use GC over RC because RC adds significant overhead, especially in multithreaded programs.