If you are laser cutting the acrylic pieces, do it in two passes. Take the machine out of focus by about 10-15mm for the first pass. It won't cut through but will create a V-shaped groove. Put the machine back in focus and cut the pieces out. You end up with perfectly chamferred edges on the top face without all the filing. Just be aware the risk of flaming when the machine is out of focus is higher, so don't leave it unattended.