Hi SleepDeprived,
While a latex “purist” would probably shudder … it may be worth considering a good quality polyfoam topper which is less costly and has more of the faster response of latex without the feeling of sinking into the mattress as much and doesn’t have the slow response or much lower resilience of memory foam. A softer Dunlop topper may also make a difference. Most sofas use polyfoam so you can use your experience on sofas as a reference point for the “feel” of polyfoam although a sofa would normally use firmer layers than mattress comfort layers because of the more concentrated weight of sitting vs lying down.
Talalay is a lower density material than Dunlop which has a more “solid” feel to it so even though it’s a somewhat subjective term … I think that there would be more people that called Talalay “jiggly” than Dunlop yes.
There is more about the “feel” of Dunlop compared to Talalay in post #7 here. The ILD of a layer is measured at 25% compression so if you were only sinking in to a layer 25% then Dunlop and Talalay would have a similar softness level as Talalay but in reality you will compress the top layer of a mattress more than 25% and in the same ILD Dunlop would normally “feel” firmer to most people than Talalay because it’s a denser and less “lively” material with a higher compression modulus so it gets firmer faster than Talalay as you sink into it more deeply. While softer versions of Dunlop that are comparable to the softest Talalay layers aren’t as common … some of the Continuous pour Dunlop made by Mountaintop or Latexco come in softer versions and there are some molded Dunlop layers that are in the lower 20’s or high teens that are more comparable to the lower range of firmness levels that are more common with Talalay as well. The component post lists some sources for all of these.
Phoenix