You have multiple personalities in one post. You don't like that the scoring is .3 higher on average across the DGPT players.
You want to make putting harder...but not that much harder...which apparently it isn't that much harder for the top pros because...you believe it to be so. You want the goldilocks zone for harder putting and even though a solution exists, your unproven solution is the right choice.
Why would smaller baskets be any different in regards to scoring separation. The better players are typically better putters. Better drivers, and better in the scramble, so they would have shorter putts on average than the lower ranked players.
Oh...and now it's 25 feet that you want to be challenging. BUT, BUT, BUT, the bolfers rarely make 25 footers, so is that really going to be satisfactory? We need to get the top players in the world to 50% at 10 feet or nothing at all!
Party on goldilocks.