hmm
if I wanted a stable filesystem across both windows and linux for one drive, should I stay on NTFS or is there a smooth option for both?
Warning: you better not jump into my mentions about using windows instead of just answering my damn question unless its about the question. just saying "use linux" doesnt help.
Goo Truther 
@lyncia honestly using a windows filesystem with Linux is not worth all the esoteric errors programs will have due to different file conventions. It might be worth trying to convert an ntfs windows install to a linux-compatible filesystem instead of the other way around. I posted about a windows btrfs converter project, but generally you will need both a converter for windows to the desired filesystem, and a patched windows bootloader with support for recognizing and booting into it.
@lyncia oh yeah that should all be okay. reading from ntfs is not destructive or risky nowadays (if you can get it working at all, but that's just... linux experience)
@thufie I assume ntfs2btrfs is the tool you mean?
@lyncia but in this case just format the external drive in btrfs and install the btrfs driver after install if you are keeping the windows system drive in ntfs, no need to convert anything.
@thufie its not the windows boot drive im trying this with, its my external data drive so i can probably skip the bootloader part?
I assume mounting a ntfs drive as read only shouldnt cause esoteric damage? I could partition out a section of empty space to be a "Cross OS" area potentially?