Without wanting to offend you, it's a pity you used small wall texture for medium and tall, so the texture appears distorted.

I love ITF conversions
I am futurista

It didn't occur to me to throw the texture into Adobe Illustrator, vectorize it, expand it, then re-rasterize it for three different sizes. I've actually withheld release of several object conversions, after discovering that your collection of those same object conversions did a better job at resolving the ghosting problem. Not sure why meshes turn translucent, but it's become a bit of a bother for me with making any Sims 3 translations.

What do you call "ghosting problem" ? Maybe I can help you.

The "solid" objects in these conversions are somehow inexplicably not 100% solid upon conversion. You can faintly see through them, and shadows of things on the other side of them.

When making conversions of objects its always important to remember that each game works differently and one needs to try hard in getting the conversion to work well on the game its been converted to.

When you look at the image of the wall as shown in your attached images from Sims4studio

You will notice that at the transition between one wall and the other, there is a distortion on it and this is because you used the wall height for small walls on all the three walls.

The way TS4 handles wall is different for TS2 AND TS3. But because you can only use one wall at a time in TS4 you may or will not notice this except you have it opened in Sims4studio.

Understanding the wall heights is essential to getting it correctly and that is what at TheJim07 was referring to in his comment. You do not use the same size of wall on all the three wall heights. You have to create them differently. When you look at Creator Wall Guideline the second topic deals with QUALITY and the last of the headings under it is UNDISTORTED and it shows there the size that each wall height has to take when making walls. If that guide is not followed accordingly to the different wall dimension, then that distortion that at TheJim07 referred to will always be there.

As an example, here is the same wall linked above made according to the wall specifications


To fully understand wall making, you can also refer to this Wall Making Tutorial

thanks

At ease, soldier. I just got off the clock. I'll look it over when I get home.