If you just want the overall volume of the delayed signal to be quieter, the Mix parameter will accomplish this for any delay algorithm. At 50% the dry signal and the delayed signal will be at equal volumes. Try setting mix between 30-40% to turn the delayed signal down a bit.
If you want to control the volume of specific delay taps, UltraTap can do this, but it’s not quite a simple delay. You can experiments with the Taper parameter, negative values will result in the first delay tap being quieter than later delay taps: https://cdn.eventideaudio.com/manuals/h90/1.5.2/content/algorithms/delay.html#ultratap
