Pereskia species- Thane, Maharashtra

Dattaji Salvi Udyan  Thane
Date: May 5, 2018 ... Altitude: about 11 m (36 feet) asl
Pereskia grandiflora  Pfeiff.

You could be correct ... But every link in your list has flowers and leaves in focus. In my posted pictures, stems are in focus, most probably very young plant - yet to assume the dense foliage. One of your links - third among last, does show the typical cluster of spines as seen in my posted pictures. I hope someone validates in positive / negative, else we will have to wait until the posted plant blooms in the garden.