I had a Trelock LS 820 that went into blink mode when you stopped pedaling and was slowing down. Problem was the brake light feature came on first and could confuse following traffic about your true intentions.

In any case, I find rear blinking lights, especially the super bright ones, can have a hypnotic or annoying effect unless there is a random mode or varied flashing sequence mode to switch to. But that choice is yours to make. Before I made the switch to dynamo hub lights, I used the inexpensive Chinese lights and put in wide angle/beam cutoff lens for both the front and rear lights (clear and red lens). Neighbors said the steady beam was preferable and made me easier to see and judge my speed and distance to their car/truck.