Can you please be more specific about the issue you are having?
When using Polyphony, there is a Freeze Performance Parameter that can latch on/off using the footswitches. This Freeze effect should not reduce in volume over time. I just froze a sound and left it frozen for 30 minutes without any change in volume. Are you experiencing something different?
Blackhole has the option to Freeze the reverb when you turn the decay parameter up, but this will gradually fade out.