You don't need software to do a load. Maybe the report feature is nice but only if you're going to show someone.
Some of what I've seem to take too much time. I mean if you have already measured everything you can enter it on a paper form and just do the math.
What if your computer breaks?
Some states require ACCA manual J now. So how much it matters depends on where you are. For example, here in Albuquerque, NM as of July 1, I need to use an ACCA Manual J approved load. Not written, done with software.
Also, in todays world, why would you even chance doing a load with anything but a certified calc? Too many lawsuits going on. back yourself with as much detail and proof as possible!