I think they are stored in register files only, in that case you have to open regedit find the SU folder and export it.
This is from the discord for SU. I haven't tried it and I'm rather opposed to registry diving, but if you are willing to gamble:
Did you want to backup your save or maybe import from someone else? All you have to do is the following. It is 100% safe and sharing or downloading another Resgistry will do nothing to you system other than delete your previous file. See warning for details.
Warning, downloading a Registry or sharing your own will DELETE whichever slot you chose (1,2 or 3) when opening it. Take that into consideration when messing with the Registry.
If you want to find your Registry to backup or share it, do the following:
1. Press Windows Key + R
2. In the Run command enter regedit
3. Once the Registry is open and you select yes for Windows to open it, look for HKEY_CURRENT_USER
4. Scroll down to Software and double click on it
5. Scroll down to Someguy and double click on it
6. Open Something Unlimited
7. Go to File and then Export. Save it to wherever on the computer
8. Upload it to Zippy
If you want to Overwrite a Slot Save:
1. Download or find where you saved a Reg File
2. Open said Reg file
3. A warning will come up saying if you want to make changes to the Registry
4. Say yes (It's safe)
5. Wait for the changes to be made and that should be it
If you want to back up your current save, and still want to download a new one, you still can. Follow the same steps and stop at 7. You can only have 1 current save for each Slot. If you know you are going to Download a Save for Slot 1 but want to keep your old one, just keep it in a safe place. When you are done, just open up the same Reg File and that should bring back your old one.
