That's the idea.
I'm generally a fan of some duration of preinfusion, but it would be an oversimplification to suggest that all beans will taste better by grinding finer.
A better way to look at this is that you can control the amount of extraction by adjusting the balance of preinfusion duration and shot length with grind level. Some coffees taste better with a higher level of extraction, and others taste really bad when extracted beyond their sweet spot. I suggest grinding finer and noting the difference. Then preinfuse even longer and grind even finer. Eventually, the coffee will get astringent and you'll want to back off the grind and and preinfuse less to get a better tasting shot.
Over time you'll find that some coffees have a wide window of tasting great, and others are much more narrow. Also, some coffees taste very different at different extraction levels, and others taste very similar non matter how you pull them. Then there's the matter of adjusting brew temperature to see if you can unlock magical flavors from a coffee that has been moved outside the sweet spot by grind and preinfusion.
Welcome to the boss level of espresso enjoyment.