Nonsteam game save file location?

[BearBrownies]

Anyone know where I can find the save game location for nonsteam games launched in console mode?

For some reason save files seem to be saved in a different location from the default heroic launcher/desktop mode location which makes it hard to utilise epic game cloud sync.

[Marlock]

each steam and nin-steam game run via protin gets their own SteamID-numbered prefix folder (the SteamID for non-steam apps is a random long number)

here is where the prefixes usually get stored:
https://github.com/ValveSoftware/Proton/wiki/Proton-FAQ#how-does-proton-manage-wine-prefixes