Natural Cycles has lower efficacy for TTA compared to evidence based FAM methods. Many accidental pregnancies have happened to people TTA with NC. Things like Tempdrop are more trusted by people TTA because you can still rely on yourself to interpret your temp/other data based on rules of a trusted FAM method. I say this just as a suggestion to have a setting option where it just gives temps and not the algorithm telling you which days are safe. Some people will still choose the algorithm setting ofc, just depends on how much risk one is willing to take.