I always appreciate stuff like this, usually I just use chown user dir/ which usually changes the perms in such a way that makes whatever I'm doing work. Afterwards I just chown back to the original user.
I should mention that this is what a psycho would do and I only do this shit when Im messing in docker and I need something to happen in a shared folder but it just doesn't.
I'd agree with another comment that this is generally overthinking it. Are you planning on expanding this game to accommodate other features and that's why being deliberate about this memory model is important? How much time are you planning on doing this in? Ask yourself questions about your goals before diving into a solution.