I'll try to answer each point you raised:
Thanks so much for the kind words, I'm so glad you enjoyed it. The save data WILL carry over to the Steam release by the way (wishlisting is available!), so make sure you do a backup! :)
HFI is made in Godot using GDScript - so there is a possibility for the game to be exported to more platforms. Right now though, my time is limited so I can't really afford to spend that extra time debugging more platforms. It does run great on the Steam Deck though via Proton. (Steam Deck is officially supported by the way) Never say never though!
I'm assuming you're referring to the Auto checkboxes on the Squire for skills - it would be helpful to save if they are checked or unchecked, thanks.
Regarding it being hard to tell when the demo is over, totally agree. This is a symptom of the demo not being fully complete. When Demo V2 comes out I'll make sure to make it very clear when you have cleared all the content.
Thanks again!