Answer:

No. as mentioned in the AutoPIPE help, a Stress Isometric feature is automatically enabled when AutoPIPE Advanced or Nuclear editions has been selected on the License Configuration / Welcome to AutoPIPE licensing dialog .

However, when using AutoPIPE Standard edition the user will NOT be able to create a stress Isometric. The following will appear:

Again,  no additional license is required. The ability to create a stress isometric using OPIM depends on the edition selected (Standard, Advanced, or Nuclear) during the current session.