Around here grinding a stock type crank is about double what you’re paying....... not including magnaflux, which I’d absolutely do on a crank that had bearings that looked like what came out if that motor.
Retail from Summit on a Scat cast 4” crank is $375, shipped free.
So, in my area, the added expense to run the 4” crank is less than $200 compared to a mag and grind.
What Jesse is going to use for pistons are way lighter than factory, so the crank will need balancing anyway.