With your poundage lowered as you have it,the spine is within spec so I wouldn't worry about it,your broadheads should be telling you that.

Inserts are roughly 1" in length,some shorter and some longer,I believe the ACC inserts are slightly shorter.

Did you use hotmelt to install the inserts?That is the preferred method for installing ACC inserts.If so,then you should be able to heat a field tip with it installed and remove the inserts and then cut,then reinstall.