so in the zip file you attached you have 5 files:
1 Cube aqua 2_79b.dae
2 Cube aqua 2_80 2019-07-04 Hash fdcfc263e973.dae
3 Cube aqua 2.80 2019-07-8 Hash a42cae160082.dae
4 Cube aqua 2.80 2019-07-9 Hash 3b4054cb586f.dae
5 Cube aqua 2.80 2019-07-10 Hash bb7b741d2f1c.dae

I tested the following cube in blender

open the file "Cube color materials 2_80 July 4 2019 last download.dae" in VSCodium, go to line 96, change the value from <float sid="alpha">1</float> to <float sid="alpha">0</float>, save the file. Does the priview in OSX Finder look as you expected ?

Download https://github.com/VSCodium/vscodium/releases/download/1.36.1/VSCodium.1.36.1.dmg , install it, open the dae file in VSCodium, change the value and save the dae file.

Not sure it helps, but change the value in that line from 1 to 0.

1. open "Cube texture July 8 2019.dae" from zip file in this ticket in a texteditor (vi, emacs, textmate, visual code studio, sublime, ...)
2. go to line 41
3. change: <float sid="alpha">1</float> to: <float sid="alpha">0</float>
4. save the file
5. check the finder if the preview of the file is correct

Are you use Macintosh yourself ?

Yes.

Let's talk about the issue, not emotions.

If I understand the ticket correctly the problem is the Preview and Quicklook function in the OSX Finder are not showing the exported object. After testing a few options I was able to make the object visible: Set the transparency value to 0 or remove the following lines in the dea file:

Thank you for the detailed report. I was able to reproduce it.

I cannot reproduce it on blender head. Any pinch zooming in the node editor or sidebar works well. Can you please try with the latest version ?