I think it’d be cool if they added all the sounds from guns and vehicles from past games into Infinite and let us choose which ones we’d like to use.
For example if you end up not liking the sound of the Infinite sniper, you could go into gun customization and equip the H3 sound effect.
Now obviously in some cases it might be a little weird with guns that behave differently than their predecessors. For example if the Infinite SMG has a faster fire rate than the H2 one, or the Infinite rocket launcher reload is different than the H1’s, the sounds won’t match up with the actions but I think it’d still be a cool thing to have in the game.
You could even go beyond guns/vehicles and customize the sound your shield makes, how grenades explode, what Elites sound like (wort wort wort come back anyone?), there’s a ton of things you could customize.
They could even make them all unlockables that you’d have to earn just like armour or skins.