After some tests i find out that 8-bit arduino and Python can send floats with maximum 3 decimal places with accuracy!!!
I also wrote a non struct code, here are the results:
NON_STRUCT
Arduino side: https://drive.google.com/file/d/1lvgT-LqQa7DxDorFF0MTe7UMpBfHn6LA/view?usp=sharing
Python side: https://drive.google.com/file/d/1gPKfhTvbd4vp4L4VrZuns95yQoekg-vn/view?usp=sharing
WITH_STRUCT better performance
Arduino side: https://drive.google.com/file/d/153fuSVeMz2apI-JbDNjdkw9PQKHfGDGI/view?usp=sharing
Python side: https://drive.google.com/file/d/1M6iWnluXdNzTKO1hfcsk3qi9omzMiYeh/view?usp=sharing
Youtube video: - YouTube