How much does each function of SimFly Linker affect my FPS?

Very little.

SimFly Linker mainly interacts with MSFS through API, and the underlying code is written in C++. When running normally, SimFly Linker almost 0 CPU, even in streaming video mode, the usage of CPU is still around 2%.

The only performance fluctuation may occur during video recording, but due to the use of Windows’ latest screen recording function (this is the main reason why Windows system requires version 1903 or above), the performance fluctuation is quite small. According to tests, in a host configuration with a 6900XT graphics card + 32GB memory + AMD 6800, using the 60fps 1080p recording option, the game’s frame rate fluctuation is about 2-3%.

Also, at the end of the recording, SimFly Linker’s use of memory will spike briefly because the program needs to read the recorded video into memory for processing and writing to disk.