This is my 6th 40 dayer so it's no big deal for me. The key is >>no whining<< and undestanding that each MC will be totally different that there really no set rule of "what's normal" It'll be what it'll be for you and trusting that whatever symptoms you get are just part of the detox process and that a bad symptom is generally a good sign that your system is doing some good detox/healing and that you just gotta suck it up and just start drinking lots of water and lemonade to keep the toxins diluted and moving out. In my book the SWF is an essential component in having a succesful fast and minimizing detox.
I give lots of credit having an easy time of my first 40 dayer cause I had actually started a juice fast and on day 5 while researching on the internet I ran into this forum and the MC and intuitively knew this was for me. Those 5 days of juiceing was a prefast cleanse that got my system in fasting mode. I also was not a caffeine drinker or soda addict.
3 days is not enough of a break to start eating after fasting for 20 +/- days and especially if you're gonna eat junk like cake etc Jumping to solid foods after the longer fast within 3 days has the potential to make you pretty sick. Especially with stuff like cake and meats etc.
You will not get the same cumulative benefits and cleansing from stopping and starting. While you do get benefits from the first part it you eat and then start again it will not be like a continuation from where you left off. It will be like starting from day one again as your system will hafta work hard at emptying itself and getting back in fasting mode.