Also, go into your settings in the project on each system and go to Media Creation. Set all items to put the media on the external drive. You can also check filter out system drive and filter out launch drive (I think that’s what they call it) so that it won’t go to the internal hard drive.
Now all your renders and motion effects you create will be written to the external drive so you won’t have those offline if you switch systems.
And even though Avid should create a new media folder when there are 5,000 items in the current one, it is recommended to keep that number at around 1200. So keep an eye on it, and when the folder inside the MXF named xxx.1 gets to 1200-1500, lock it off by changing the .1 to .2 and then Avid will create the new .1 folder the next time media is written. If you have recently rendered or imported anything make sure the two nonmedia files, the database ones (can’t remember the extensions offhand) are of a newer time than the media files so that they have all the media files indexed or the newest ones might appear offline.
If you do get an OMFI media folder, iirc, the current folder has no .#, so put a .1 at the end and then Avid will create the new folder when you create more media.