Add to "Active Choices Parameter" and "Active Choices Reactive Parameter" new configuration parameter. This parameters defines, when filter must start work.

Eg, When you sets "4", filter work, when filter pattern length equals 0 or greater than or equal 4.

Why?
In my work I create jenkins job, which has a one Active Choices Parameter (eg. name PARAM_A) and few Active Choices Reactive Parameter (name PARAM_B, PARAM_C, PARAM_D...) depends on PARAM_A.
Script in PARAM_B, _C, _D doing something for a few seconds (2-3s).
When the filter is working (PARAM_A) when you type 1 or 2, 3 characters, it is not very effective, with such a configuration parameter.