All things being equal, If you are dedicated to your long term improvement (2021 and beyond) and you have the mental ability to get through the workouts (usually a netflix membership is the price of admission) go for it. Just know that you probably won’t see FTP gains until the build phase but 2+hr power will improve (in my experience).
I am currently doing SSB MV coming off a modified and extended TB HV. I find that adding volume to the SSB plan is like playing with fire. I’m used to 12+ hour weeks of Z2 & Z3 work but adding in VO2 and threshold/SS work in SSB is another story. Sweet spot work doesn’t feel that hard but I’ve found it needs to be treated with respect, and proper recovery. On lower intensity, I would pile 3-5 workdays back to back before taking a recovery spin or off-day. In SSB the recovery becomes extremely more important and timing is everything. Those 2hr Z2 rides that you think are easy actually come with quite a bit of stress and when you pair them with SS and VO2 work without sufficient rest in between; things fall apart. What I have learned in the last couple of weeks is that Z2 is not “easy” or “recovery” (duh) and shouldn’t be in an easy day.
Sometimes less is more and sometimes I’m too ambitious to understand that.