PA34 pilot reported they were unable to stop on the runway remaining during a high speed taxi; which resulted in a runway excursion and a propeller hitting airport lights.

Narrative

I was performing a high speed taxi on Runway XX at ZZZ to check an aircraft that had just completed annual inspection. It was intended that a check flight would be done if no issues were discovered in this maneuver. Pre-maneuver accelerate stop/distance was calculated an I determined there was a 25% safety margin. I accelerated to 75 MPH (VR); raised the nose off the ground slightly; and then cut power and started braking. I was unable to stop in the remaining distance and attempted to exit the runway at the last taxiway; but was going to fast to do so without significant risk of damage from side loading. I chose to go off the end of the runway/taxiway at that point and complete the stop in the grass area around the pavement. In exiting the pavement; I struck 2 lights with the left propeller. I was able to taxi back on to the taxiway and returned to ramp and shut down. I believe that I failed to complete the maneuver as planned; starting braking too late. In the future to prevent this; it would be a good idea to do it at half speed first to uncover any unforeseen problems.