Folks, I continue to see considerable energy invested by people who are quite literally obsessed with "drawing out" the roast development time-frame between FC and SC to the longest possible period in the hope it will yield a magic result. It all depends on your equipment, roasting method and many other factors that occur in the leadup to FC. I think it would be very difficult to apply a general rule across the myriad of different types of roasters that people use. I will put my hand up as one person who has gone from one extreme to another over many 1000's of batches to search for the holy grail in determination of the best "target RD time". One thing I've realized is I used to think it MUST be 5 mins or it will just be shite - nope, 3 mins can be superb for some beans and profiles and a lot has to do with thermal transfer and air flow. Whilst this next statement may raise some hecklers, in fact, under some circumstances 3 mins can be a safer option than 5 mins. This is what I've learned for my style of roasting. I'm not trying to steer people down a rabbit hole.....just use your cup as a guide, not necessarily the stopwatch.