even out led bars or keep one 30 inches higher(losing 1/2 par)

You want the lights as close to the plant as possible. It doesn't matter is you are using multiple lamps from different angles you want every lamp as close as possible. You can test if the lamp is not too hot for your plants by placing your hand under the lamp on the same distance that you want to place it from your plants. Keep your hand there for 1 minute and if the heat does not feel unpleasant warm on your hand your plants will be fine!