That is a valid reasonable concern. I have done 10 +/- 40 dayers and have done variations of only doing the SWF daily at the begining cause the tea gave me horrible cramps to doing it on alternative days after 2 weeks to doing it every 2 to 3 days after 2 weeks and I've been fine.
Like you I am one of those folks that has been regular and never have had troubles with bowel movement my whole life. Nevertheless one has to be judicious post fast in introducing regular foods after a 40 dayer to get the system adjusted and back to regular eliminations. One needs to be gentle on the system and gradual after a long fast. Doing probiotics is always a good idea to bring digestion and eliminations back on track after any fast and particularly the longer ones.
I can't remember who it was but it was an experienced person who's judment I trust ( maybe Zoe) that pointed out that since the system is empty of solids it doesn't respond the same as far as becoming dependent from prolonged use of laxative teas.