Hi,
To force a separation between objects in contact with one another they need to be significantly different enough, like having different wall counts or infill settings (see Reinforcing parts by designing modifiers in Fusion ). But I don’t think that’s what you want here (though it may work since PLA shouldn’t stick to TPU).
To create a proper gap, you’ll need to carefully design the model & supports so there is at least a one print-layer-thick gap between the objects. Eg. if you’re slicing using 0.2mm layer height, make sure your gap is at least that large. This is a similar concept to designing print-in-place parts like joints or self-supporting parts… there needs to be a physical gap which the slicer won’t ignore, but not too much so the upper layers deform.
To further refine the gap you could use variable layer heights in the slicer, either via height modifiers (r-click object to add some) or the layer height “painting” tool in Studio (top toolbar), both in Prepare mode. You could fine-tune the layer heights around the support/model transition points. Only possible negative here is that it will also affect the actual model at those heights as well.
Having said all that, the built-in support generator is pretty flexible and you may be able to get a better result by fine-tuning those settings and checking the result layer by layer. The big advantages here are that the height between support and model can be finely tuned (much easier than what I describe above), plus different patterns can be employed as interface layers. Among other options. What it generates by default is usually junk(y) except in the simplest situations… I always have to fine-tune it to my picky satisfaction.
HTH,
-Max