Zercher Holds on Best Damn

I have been doing the Best Damn Workout Plan 2 for 3 months now and for this time I have added a Zercher Hold on the end of a pull 1 days as an ab exercises.
In my home gym I only have a max of 200 pounds including the bar for my barbel.
So i have basically been doing 200 pounds for 20, 25 and then 30 seconds with 2 minute rests in between.

My two questions are:

Should I ramp up the Zercher hold with a 60%, 80% and 100% weight? So it would be 120 lbs-30 seconds, 160 lbs- 30 seconds, 200 lbs- 30 seconds.

On one of the t-nation articles you recommend doing a very heavy weight for 6-9 seconds, since I don’t have any heavier is it still worth it to have my max set as 200 pounds for 30 seconds?

Thanks alot.