they will be much harsher
Nah, you won’t really notice any difference. I’ve got straight forks on my cross bike and it’s really no harsher than one with curves.
It really does depend on what material it is, A straight carbon fork will be more compliant than a curved Alloy one, BUT, Carbon straight Vs Carbon Curved or Steel Straight Vs Steel Curved, Then the Curved ones will always win due to the curve both reducing the amount of “buzz” and also flexing to add a degree of suspension.