I made a quick simple save/load system:
It’s barebones rn and only supports parts, characters, children and sounds but I might add more to it later.
It also allowed you to fling yourself quickly:
Check it out here:
Keybinds:
F6 - Quick save
F7 - Load Quick Save
It’s not open-source hence why it’s here. Might open-source later though.
Great Work!
Was the fling intentional or not? because that sounds like a bug to me.
Keep it Up! 
Nope haha, it’s a side-effect of shift lock and spamming F6 and F7, would be funny if someone used it to speedrun a roblox game
Its been 3 years, will you ever open source it? it would be REALLY useful for future singleplayer games on rablax