As far as an RTO is concerned, since the weight remains on the wheels throughout, the EEC keeps the engines at minimum ground idle (normal ground idle setting)
Assuming the RTO is began with thrust levers at take off position, then by the time you whip into reverse at high speed the N1 would be passing about 60 percent by the time the power had started to spool down and reverse levers actuated. In other words the situation should never arise where the engines have spooled down to idle thrust (23 percent N1) before you pull the levers into reverse thrust.