Boeing have already issued guidence. If you have just the amber reverser unlocked light you should continue.
malfunctions worthy of an RTO between 80 knots and V1 to four conditions: fire or fire warning, engine failure, or if the airplane is unsafe or unable to fly.
They have two notes in the QRH
"Only multipule failures could allow the engine to go into reverse thrust"
"Unstowed reverser sleeves produce buffett, yaw, roll and increased airplane drag"
The probability of an actual reverser deployment is "unlikely" (Boeings words)
The probability of a cock up during the high speed abort; likely according to the stats.