Derm is switching me from generic Accutane to Absorica LD. How long should I be on it if I've already hit my target dose?

I've been on accutane for about a year, and although it's helped, I still have lingering breakouts and pimples. My derm has switched me to absorica LD to see if I absorb it better. Absorica LD is recommended to be taken for 16-20 weeks, but I already surpassed my target dose with the generic accutane. How long should I take the absorica for if I end up clearing up in the first month?