Hi there - seems that the problems you are having have very little to do with Hex, but your understanding of how the applications work - let’s see if we can help you out:)
Firstly, so we can all be on the same page, the application you are using is Daz Studio (commonly referred to as DS) - Daz is the name of the company that owns it. Secondly, there is no direct import between DS and Hex - there is the bridge, but that is a whole other thing.
There are two methods of getting stuff between DS and Hex - one is exporting as .obj from DS, importing into Hex, exporting as .obj from Hex and importing into DS. Then there is the direct bridge - never mix these two functions, or will get proportion problems.
When exporting from DS, make sure that the figure is in the base (no smoothing) mode, export at Studio dimensions, import into Hex at 1.00, export from Hex at 1.00 and import back into DS at Studio dimensions. You won’t have any proportion problems with that method.
Sending to Hex via the bridge - Hex must be closed, so the bridge can open it. Make sure that the figure is at the base smoothing level. This will not give you any proportional problems.
On the matter of proportions - there is no standardization throughout the 3D world - every application handles proportions differently, so this isn’t confined to Hex-DS. Regardless of what other applications you use, you will have to learn about the various ratios used.
The DS-Hex bridge is intended to be used to make morphs for DS products, so using that will keep proportions intact. Bear in mind that making a morph involves moving vertices around - nothing else. If you alter the shape by adding/subtracting vertices, such as using the Boolean function, (or adding a tail) it alters it drastically and it is no longer the original figure, so the UV maps won’t work and therefore the textures won’t work.
You are quite right that original .obj’s exported from Hex will come into DS at a very small size - that is common throughout the 3D world - the difference between Hex and DS is close to 1000% (I forget the exact figure), so you can either export it from Hex at 1000 and import to DS at Studio proportions, or export from Hex at 1.00 and import into DS at 1000%. You’ll soon learn that size doesn’t count - it is proportion which are important.
You referred to texturing in Hex - depends what you mean by texturing. There are three methods in Hex - you can 3D paint, or import a texture, or simply colour it. DS isn’t all that good at reading texture maps directly and this is true of many 3D apps. Plus every application handles textures differently. For instance, I just tested sending a cube and a sphere, coloured differently, from Hex to DS. Using the bridge, they came in just fine. Exporting as .obj, the cube came in perfectly, but the sphere seemed to have no colour, but when rendered, they were both fine, although the colours weren’t exactly what they were in Hex.
There isn’t a lot of point in texturing in a modelling application - best to do it in the rendering application, simply because all render engines handle colours and textures differently. If it is intended for DS, rather define your shading domains and materials in Hex and do the texturing in the surfaces function in DS.
If you really want to do 3D painting or importing textures into Hex, when you export the .obj, it will save as a .png file in the same location as the .obj. In DS, using the surfaces function, navigate to that folder and import the texture.
Lastly - avoid using the Boolean function like the plague - it is useful is some instances, but only if absolutely necessary. It really messes up the geometry and unless you have a lot of time and expertise to fix it, you end up with a mess that DS really doesn’t like. There are many methods of doing things without Boolean, which is, after all, simply a shortcut to doing something you could model anyway.
Hope some of this will help you towards the next level in your endeavours:)