You can do fun things, like tail logs to a file using linux and simultaneously analyze the file using windows tools.
You shouldn't access files in WSL using windows, but the other way around it's absolutely ok.
So if my projects are at C:/Development/Projects/...
Then I just open /mnt/c/Development/Projects/... on WSL
I haven't had any permission problems, not even once.
Same for Docker for Windows. It uses Hyper-V + some network disk sharing magic, which makes directory mounts into docker containers work great. So sometimes, like, when I need to debug a non-cross-platform linux program. (WSL doesn't handle process forking well, so some debuggers, like Go Delve don't work) I just do something like
docker run -v C:/Development/Projects/MyProject:/mnt/MyProject -it ubuntu /bin/bash