I don't care about onedrive, but I did run CM from network shares (SMB). from my server in my LAN.
I do not know whether onedrive is comparable to that or whether microsoft hacked up things to be weird.
Many wargamers are only comfortable with computer games if they do all the calculations and at the same time the calculations are so transparent that you can re-do them yourself. Hexes help a lot here compared to arbitrary move ability.