How much extra inconvenience would it be to make the ends and side molds without any ladders/grabs/brakes and make a run of a few 100 cars without the aforementioned details. Sort of like a private run. Following up this run, go back and engrave the details for the primary runs.
Years ago the late Terry Wegmann made a mold for an early Dreadnaught end to replace the ends on an Athearn reefer. He made the mold without the engraved ladder brackets and ran a few test shots. Satisfied, he went back and added the ladder brackets. He regretted not making a lot more of the 1st shots. Maybe now while you are still in the design period you might consider this? Especially for the ends, which are far more work to remove detail than the sides.
Thanks for continuing to bring forth new freight cars,