Maybe not as robust of a solution as you are looking for, but I have a simple script which runs immediately at the beginning of a task sequence as the first step (beginning time) and at the end of the task sequence as the last step (end time):

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1. Get beginning time (e.g. $BeginningTime = Get-Date)
2. At end, get end time and subtract from beginning time ($Duration = $BeginningTime - $EndTime) then you can get amount of time surpassed like $Duration.TotalMinutes

I just have a .csv file which the script adds a row with other task sequence variables like the TS Name, model of computer, specs of computer, assigned user (we capture this during OSD), etc.

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Here's how to read TS variables with PowerShell: https://docs.microsoft.com/en-us/sccm/osd/understand/using-task-sequence-variables