I've checked some sources. In https://gafferongames.com/post/floating_point_determinism/, a developer of SupCom confirms that they already use the IEEE754 float standard to avoid desync problems with different x86 processors (AMD and Intel). They use the _controlfp command to determine how floating-point calculations work. The problem is that on ARM Windows, _controlfp has a slightly different effect - it affects a different set of registers (https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/control87-controlfp-control87-2?view=msvc-170).
This is only a guess, but it seems like we can just rewrite some code and change the used float registers.
I'm not sure that this will solve everything, but it looks like a good first attempt.