@laurentr I like this method. One little trick to get around the 'percentage' rather than 'real time' output is to use an Envelope Generator++ and set the final value to the same number as your 'time'. That gives you seconds as an output:
I think I'm right in saying the difference between a standard Envelope Generator and an Envelope Generator++ is the '++' version outputs values between Min-Max rather than 0-100. Very useful for negative numbers and when you want to 'see-what-you-get' without invisible scaling happening.