For me, I wouldn't be the least bit concerned about the seam area. Not that flow is an issue in pc use, but being a synthetic filter I'm sure this filter flows well and would hold up just fine in all areas when used as intended/spec'd.
I appreciate you posting a virgin Amsoil filter, that said these are not a typical WM $3.27 Classic. If I purchased it I'd want to use it first to get the value from it. But, that's just me.