The design elements you mention indeed do it all. A softer insert for example can make a firmer ball feel softer at impact but its lighter weight also allows for more perimeter weighting forgiveness and stability. Odyssey’s White Hot and Scotty Cameron’s aluminum inserts do this admirably.
If I was Furyk I’d be tempted to tell Schauffele “Hey bud win this event and you’re on the squad.” Then see how he plays. If he rises to the challenge? You’ve got another rookie assassin. Crumbles? Finau looks plenty capable. Nice Jeff. Not quite Machiavellian but crafty. I like it.
It’s true that modern golf balls are extraordinarily durable but the reality is that you risk losing some significant yardage off your driver (up to 5 yards) and accuracy with your wedges if you try to milk one ball for too long.