We discuss reverse at the start of the build because it has to make sense with the donor bike, drivetrain and finished weight. It is especially useful for touring machines, riders with limited leg strength, sloping driveways and everyday parking where you cannot always choose the perfect angle.
If your current trike has no reverse, send us the exact model and photos of the drivetrain and rear end. We can tell you whether an upgrade is realistic. If you are planning a new build, reverse can be considered alongside stability, wheel track, braking and storage.
The quickest way to get a useful answer is to send the bike model, your location and a short video or photos of the existing machine.