Hello, thank you so much for your support! We strive our best to ensure that our game is backward-compatible and that your old saves would work with every future update. There should be no issues with your saves or progress due to updating the game, but if you are still concerned about potential data loss, please feel free to make a backup of your save folder before doing so:
Windows: /Users/<YOUR_USER>/AppData/Roaming/RenPy/Na Daoine Maithe
Mac OS X: ~/Library/RenPy/Na Daoine Maithe
Linux/Other: ~/.renpy/Na Daoine Maithe