sorry probably just my bad use of term's but Ive always refered to to float as when the valve dosnt close as quick as the cam allows, where as bounce as such is the effect where the engine hits the brick wall and wont rev any harder while under load

what I meant was that the engine can be floating the valves at say 4500 and losing some power well before the 6500 point where the engine wont rev out any further due to valve bounce

I didnt think that I said that valve bounce wouldnt reduce power as it obviously does

sorry for the miss understanding