This automatically scales your full range 0-1023 video to hd 64-940 legal for layoff and render. Beware the internal scopes do not represent the true output in this mode. You must run through and external scope to see the results of using this function. You also must grade with it on or off you cannot change it without trimming your list.. As you will see by looking at your display the output changes when you toggle this function.
2nd is work in full range and build a lut to limit at 64_94.
Do you work normal range for TV delivery?
I have always done that myself, but figuring out today when moving my final file into an Flame with a lot of other commercials (from other production companies) that they were all full range except my file. Adstream let you deliver with true black for TV.