Sorry, also in the ‘not helpful’ camp I’m afraid.
My partner is 5ft 4. She has the same leg length, and thus the same overall BB to saddle requirement as I do at 5ft 10 – I am a mens ‘large’ by the charts on most manufacturers but have stumpy legs that mean I have to choose my frames very carefully to get the right reach/seat-tube ratio, and select my dropper post lengths and crank lengths very carefully.
‘This frame comes in extra small’ is not really helpful at all, as its bascially meaningless.
(For reference, some manufacturers are great at the reach/seat tube ratio thing now as @Littleman pointed out – Santa Cruz, Orange, Ibis… some are terrible, Orbea, older Scotts, Trek etc etc…)
This needs a much more detailed study of geometry, and peoples body shapes to be useful.