Just a few more thoughts...
I think I got my latex mattress choice SO wrong for so long by being thrown off by the terms "medium" and "soft." When I visit mainstream mattress stores, my experience is soft is VERY soft. I'm thinking of the polyfoam pillowtops that are nice at first but wear down and have led me to wanting something more medium and durable.
When I decided to experiment with latex, a material new to me, I ended up WAY overshooting by trying beds that were described as "medium" with top layers that were between 28-32 ild. I liked how firm they felt (I still do, despite by body screaming otherwise in the morning), plus I thought I could fix my side with a topper while my husband, who is 5'9, 160 lbs, would be just fine. I never figured out why all the toppers of various heights and densities couldn't work--pressure points were fixed but then my spine ached. My theory is that when your petite, 3" is already quite far away from the base layer, and adding an extra inch or two just adds new problems.
What was humbling to learn when I finally switched to the Katherine soft, and I should have known better, is just because a bed is called soft, it can still be SUPER firm if you are low weight. Again, when I lie down I like the quiet, solid, firmness of this bed, but the fact is my body is so stiff in the morning. 24 Ild of talalay latex (or dunlop which I too have a suspicion is in my Katherine). is still WAY WAY too firm. I'm STILL NOT in the ball park. Interestingly, the Natural Escape has a top layer of dunlop with an 18-22 ILD. Its product description makes clear it is medium firm, and so I steered away from it, but it must be similar to the "soft," or what it know listed as the "plush," Katherine (24 ILD talalay). Silly me for letting the product description make me hope it would be be soft for me and allow the right sinkage. Now I'm adamant about first paying attention to the actual ILD.
I think petite people--say 130 lbs or less starting at 5'0--interested in experimenting with latex should start with top layers that are in the 13 to 19 ILD range, preferably 13 and preferably talalay which seems to have more give than dunlop for lighter bodes. I think the thickness of that layer and the firmness of what's underneath would all have to be tweaked, but something in that range is at least a good starting point for the right sinkage, and would help avoid all the time and expense of trying things WAY out in left field. Soft latex is such a different animal compared to soft polyfoam or soft cotton or wool batting for petite people. (I think hotel beds do not hurt us because they have all that fluffy polyfoam in the pillowtops--as petites it's no problem to deal with that. Latex is exotic for us, I swear! Even the utterly thin and flimsy innerspring of my most recent hotel stay was fine and welcome my by body compared to my super high quality latex hybrid/so-wrong-for-me bed ).
Another reason I think petites new to latex get it quite wrong is that ILDs of 13 to 19 in the comfort layer don't seem that common. When I ran across them in my search for a latex bed, those low ILDs seemed extreme.
I would ask Tim if he has mattresses with latex top layers that are between 13 and 19 ild and if there are floor models to try out. When I read their mattress specs, it seems that very low ILDs are not available, just taller and taller toppers.
I too get seriously stressed out by having to return things--it's such a headache and takes so much time and energy for everybody. I think I used up all my good graces by returning my medium ONE YEAR later. Tim was EXTREMELY kind to put in a soft layer after all that time, but when I received it and called him distraught knowing it was still much too firm, he was clear I would have to bring in the mattress myself--even though I said I didn't mind how much it would cost--if I wanted a customized layer of 19 ILD or less. My husband and I can barely rotate the thing, let alone get it into a rental truck and drive the 50 miles.
For now I'm sleeping on our guest bed--a Brooklyn Bedding 3" inch blended talalay latex topper (19 ild) on top of a super stiff Tuft and Needle bed from 2013. This feels fine. Just looking for something less cut-and-paste.
Meanwhile, I wold love to hear what you end up with!