Moved this to the Niche forum. ☺️
Actually, the increasing lifespan option is already being added to the game! You can look here for some pictures and more information:
And here if you want to see some of the other Sandbox options that will be added (and you can vote on the unadded ones if you like them!)
https://strayfawnstudio.com/community/index.php?/forum/70-customization-options-for-sandbox-mode/
AND here if you want to see what else will be added to the game!