MC909 is closest to Fantom-S, but both descend from the JV/XV. Roland actually released a patch compilation of JV/XV patches for the Fantom-X series, but unfortunately it seems you can only load it via their decades old proprietary software detailed in this youtube video:
https://www.youtube.com/watch?v=oOF67DuqnYw
And from what I've gathered, they're not quite 1:1 as the Fantoms have slightly different and mostly newer ROMs. So some manual tweaking will probably be in order. You can find the original Roland Fantom-X_XV_Data.sit file to download though.
It's kinda crazy that the MC909 omitted any kind of patch dump from what I can tell. Even with a USB port and marketing talk about sharing on the "world wide web", there's not really a straightforward way to save and load a patch. From what I've read (digging deep in these forums), the only way to save/load patches between 909s is to create a song with all the patches you'd like assigned to the 16 parts, and then save that .mcs file on your computer. You have to be mindful of what ROMs your patches are using (internal or user/card), but you can then load that .mcs song file on another 909 and your patches will be there
