Excepting fitting needs that are way off the bell curve (and a small woman of grand age might just sit at the fringes of normality) TT slope is a non issue as long as certain specs are respected. Stand over height, post extension, bar/stem height, are some obvious ones. But stay length and seat stay angle WRT foot length and type of rear brake is an aspect usually found out after the bike is assembled and being delivered I've seen heel contact with some cantis as example and why it's rare to see cantis on mixte bikes. Another aspect of TT slope is how long the ST becomes and if that will fit a bottle or pump. Andy