What started as grinding Away moist grout on shower floor tile Turn into complete removal as well as bottom 6 inches of wall tile. Working on removing the old drain. No sign of weep holes (yet?). The Sxhutler Kerri system looks easier for a first time DIY but is it really necessary or beneficial to completely remove the mortar bed? Can I just patch up a couple spots and put a new membrane over it ?
I have left old mortarbeds in place in showers. In your case, your bed looks quite good.I do make a habit of smoothing the old surface, so there aren't areas with gaps or pinch points to catch the new membrane on. As long as your new surface meets well with the drain (as in the membrane will seal around the drain and won't be lifting the tile so high you have to grind the edges) it should be fine.