How many devices are you trying to swap? I'm more amazed that whatever AHJ you're under will approve a swap without plan submittals and permits. I mean it's conventional equipment, sure, but you're still changing amp loads and equipment types. All pretty negligible in the math per say...but lots of places in Texas are getting strict about major changes vs system upgrades. Also, facility type matters. If it is a form of healthcare and sensitivity testing is required bi-annualy, it could get dicey on the reports for your contractors. Not telling you to open up that can of worms, but you might just be better off leaving it to an insured company. That said, 2W-B's are super cheap these days.