I currently maintain a legacy C+ app that runs on x86/x86_64/armhf linux, all 4 android archs and x86/x86_64 windows.
The linux compilation phase takes 1m, whereas on windows (using MinGW) it takes 10m. It’s not the end of the world, but would the MS compiler be faster? Better?
From the perspective of the CI guy: Just cross compile from Linux.
You can get the Windows compilers for free - just CLI build tools are enough for your case. The setup can be a bit messy, though. Also, if it’s a GCC only codebase so far there’s a decent chance it has constructs which will not compile on MSVC. It will not necessarily be faster, though.